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United States Legal Document 

$3T All citizens and residents are hereby advised that 

this is a legally binding document duly incorporated by 

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requirements as hereby detailed within may subject you 

to criminal or civil penalties under the law. Ignorance of 

the law shall not excuse noncompliance and it is the 

responsibility of the citizens to inform themselves as to 

the laws that are enacted in the United States of America 

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ASME B31.9 (2008), Code for Pressure Piping, 
Section on Building Services Piping, as required 
by the laws of the State of Iowa as stated in 
Chapter 91 of the Iowa Administrative Code, 
Rules for Boilers and Pressure Vessels, Section 
91.1 (5) . 



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Building 
Services Piping 



ASM Code for Pressure Piping, B31 



AN AMERICAN NATIONAL STANDARD 



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Copyriglit © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



ASMEB31. 9-2008 

(Revision of ASME B31.9-2004) 



Building 
Services Piping 



ASME Code for Pressure Piping, B31 



AN AMERICAN NATIONAL STANDARD 




Copyright © 2008 by the American Society of Mechanical Engineers. XgJ 

No reproduction may be made of this material without written consent of ASME. ^£3 



Date of issuance: July 14, 2008 



The next edition of this Code is scheduled for publication in 2011. This Code will become effective 
6 months after the Date of Issuance. There will be no addenda issued to this edition, 

ASME issues written replies to inquiries concerning interpretations of technical aspects of this Code. 
The interpretations are included with this edition. 



ASME is the registered trademark of The American Society of Mechanical Engineers. 

This code or standard was developed under procedures accredited as meeting the criteria for American National 
Standards. The Standards Committee that approved the code or standard was balanced to assure that individuals from 
competent and concerned interests have had an opportunity to participate. The proposed code or standard was made 
available for public review and comment that provides an opportunity for additional public input from industry, academia, 
regulatory agencies, and the pub!ic-at-large. 

ASME does not "approve," "rate," or "endorse" any item, construction, proprietary device, or activity. 

ASME does not take any position with respect to the validity of any patent rights asserted in connection with any 
items mentioned in this document, and does not undertake to insure anyone utilizing a standard against liability for 
infringement of any applicable letters patent, nor assumes any such liability. Users of a code or standard are expressly 
advised that determination of the validity of any such patent rights, and the risk of infringement of such rights, is 
entirely their own responsibility. 

Participation by federal agency representative(s) or person(s) affiliated with industry is not to be interpreted as 
government or industry endorsement of this code or standard. 

ASME accepts responsibility for only those interpretations of this document issued in accordance with the established 
ASME procedures and policies, which precludes the issuance of interpretations by individuals. 



No part of this document may be reproduced in any form, 

in an electronic retrieval system or otherwise, 

without the prior written permission of the publisher. 



The American Society of Mechanical Engineers 
Three Park Avenue, New York, NY 10016-5990 



Copyright © 2008 by 

THE AMERICAN SOCIETY OF MECHANICAL ENGINEERS 

All rights reserved 

Printed in U.S.A. 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



CONTENTS 



Foreword v 

Committee Roster vi 

Introduction viii 

Summary of Changes x 

Chapter S Scope and Definitions 1 

900 General 1 

Chapter H Design 9 

Part 1 Conditions and Criteria 9 

901 Design Conditions 9 

902 Design Criteria 9 

Part 2 Pressure Design of Piping Components 11 

903 Criteria for Pressure Design of Piping Components 11 

904 Pressure Design of Components 11 

Part 3 Selection and Limitation of Components 14 

905 Pipe 14 

906 Fittings, Bends, and Intersections 15 

907 Valves 15 

908 Flanges, Blanks, Gaskets, and Bolting . . 1.5 

Part 4 Selection and Limitation of Joints 15 

910 Piping Joints 15 

911 Welded Joints 15 

912 Flanged Joints 16 

913 Mechanical and Proprietary Joints 16 

914 Threaded Joints 16 

915 Flared, Flareless, and Compression Joints 16 

916 Bell and Spigot Joints 16 

917 Brazed and Soldered Joints 16 

Part 5 Expansion, Flexibility, and Support 17 

919 Expansion and Flexibility 17 

920 Loads on Pipe-Supporting Elements 20 

921 Design of Pipe-Supporting Elements 20 

Part 6 Systems 24 

922 Design Requirements Pertaining to Specific Piping Systems 24 

Chapter ill Materials 26 

923 Materials — General Requirements 26 

Chapter IV Component Requirements and Standard Practices 28 

926 Dimensions and Ratings of Components 28 

Chapter V Fabrication, Assembly, and Erection 34 

927 Welded Fabrication of Metals 34 

928 Brazing and Soldering of Metals 39 

929 Bending 40 

930 Forming 40 

931 Heat Treatment 40 

934 Fabrication of Nonmetals 40 

935 Assembly 41 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



Chapter VI inspection, Examination, and Testing 43 

936 Inspection and Examination 43 

937 Leak Testing 44 

Figures 

900.1,2 Code Jurisdictional Limits for Piping — Drum Type Boilers 2 

904.2.2 Nomenclature for Miter Joints 12 

921 .1 .3-1 Support Spans for Standard Wall Steel Pipe 21 

921.1.3-2 Support Spans for Copper and Thermoplastic Pipe 22 

927.4.3-1 Fillet Weld Size 35 

927.4.3-2 Minimum Weld Size, Setback, and Depth of Insertion for Slip-On and 

Socket Weld Flanges 36 

927.4.3-3 Minimum Welding Dimensions for Socket- Welding Components Other Than 

Flanges 36 

927.4.5-1 Acceptable Welds for Flat Heads 37 

927.4.5-2 Unacceptable Welds for Flat Heads 37 

927.4.6-1 Typical Weld Branch Connections 38 

927.4,6-2 Typical Weld Details 38 

Tables 

902.4.3 Joint Factors, E 11 

904.2.1 Pipe Thickness for Bends 12 

917.3 Rated Internal Working Pressures of Joints Made With Copper Water 

Tube and Solder Joint Fittings, psig 17 

919.3.1 Moduli of Elasticity and Thermal Expansion Coefficients 18 

921.2.2 Capacities of Threaded ASTM A 36 Steel Rods 23 

926.1 Component Standards and Specifications 29 

926.2 Standard Practices 33 

Mandatory Appendices 

I Stress Tables 47 

II Allowable Pressures for Nonmetallic, Nonplastic Pressure Piping 57 

III Reference Standards 58 

IV Preparation of Technical Inquiries 61 

Nonmandatory Appendices 

A Nonmandatory Quality System Program 62 

B Seismic Design and Retrofit of Piping Systems 63 

Index 67 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



FOREWORD 



The need for a national code for pressure piping became increasingly evident from 1915 to 
1925, The American Standards Association initiated the B31 Project in March 1926 to meet that 
need. The American Society of Mechanical Engineers proposed the work and has served as 
sponsor since its inception. 

The first edition was published in 1935 as the American Tentative Standard Code for Pressure 
Piping. To keep the Code abreast of developments in design., welding, and of new standards and 
specifications, as well as of developments in service conditions, new or supplementary editions 
were issued as follows: 

B31. 1-1942 American Standard Code for Pressure Piping 

B31. 1-1942 American Standard Code for Pressure Piping 

B31.1a-1944 Supplement 1 

B31.1b-1947 Supplement 2 

B31. 1-1951 American Standard Code for Pressure Piping 

B31.1a-1953 Supplement 1 to B31.1-1951 

B3 1.1 -1955 American Standard Code for Pressure Piping 

In 1955, a decision was made to develop and publish separate Code Sections for various 
industries. The current Sections are: 

B31.1 Power Piping 

B3L3 Process Piping 

B31.4 Pipeline Transportation Systems for Liquid Hydrocarbons and Other Liquids 

B31.5 Refrigeration Piping 

B31.8 Gas Transmission and Distribution Piping Systems 

B31.9 Building Services Piping 

B31.ll Slurry Transportation Piping Systems 

In 1969, the American Standards Association, renamed the United States of America Standards 
Institute, became the American National Standards Institute (ANSI), and the B31 Sectional Com- 
mittee became the B31 Standards Committee. In 1978, The American Society of Mechanical 
Engineers was granted accreditation by ANSI to organize the B31 Committee as the ASME Code 
for Pressure Piping, with Code Sections designated as ANSI/ ASME B31. 

Need for a separate Building Services Section of the Code for Pressure Piping was recognized 
for several years. This new Code Section, ASME B31.9 Building Services Piping, first issued in 
1982, was developed to fill that need. 

The Code has intentionally been written on a conservative basis in order to avoid the necessity 
for complex design, fabrication, and inspection criteria. For this reason, application of this Code 
is expected to be simple and straightforward. 

Metric (SI) units have been added in parentheses after U.S. Customary units. This Code is based 
on U.S. Customary Units. 

Following approval by the B31 Main Committee and the ASME Board on Pressure Technology 
Codes and Standards, and after public review, this Code Section was approved by the American 
National Standards Institute on April 1, 2008. 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



ASME B31 COMMITTEE 
Code for Pressure Piping 

(The following is the roster of the Committee at the time of approval of this Code.) 

COMMITTEE OFFICERS 

M, L. Nayyar, Chair 

K. C. Bodenhamer, Vice Chair 

N. Lobo, Secretory 



COMMITTEE PERSONNEL 



R. J. T. Appleby, ExxonMobil Upstream Research Co. 

C Becht IV, Becht Engineering Co. 

A. E. Beyer, Fluor Enterprises, Inc. 

K, C. Bodenhamer, Enterprise Products 

]. S. Chin, TransCanada Pipeline U.S. 

D. L Coym, Worley Parsons 

J. A. Drake, Spectra Energy Transmission 

P. D. Flenner, Flenner Engineering Services 

D. M. Fox, Atmos Energy 

J. W. Frey, Stress Engineering Service, Inc. 

D. R. Frikken, Becht Engineering Co. 

R. A. Grichuk, Fluor Corp. 

R, W. Haupt, Pressure Piping Engineering 

L E. Hayden, Jr., Engineering Consultant 

G. A. jolly, Vogt Valves/ Flowserve Corp. 

N. Lobo, The American Society of Mechanical Engineers 

W. J. Aflauro, American Electric Power 



J. E. Meyer, Louis Perry & Associates, Inc. 

E. Michalopoulos, General Engineering and Commercial Co. 

JVS. L. Nayyar, Bechtel Power Corp. 

I. J. O'Grady IS, BP Exploration (Alaska) 

R. G. Payne, Alstom Power, Inc. 

J. T. Powers, Worley Parsons 

E. H. Rtnaca, Dominion Resources, Inc. 

M, ). Rosenfeld, Kiefner & Associates, Inc. 

R. J. Silvia, Process Engineers and Constructors, Inc. 

W. J. Sperko, Sperko Engineering Services, Inc. 

G, W. Spohn Hi, Coleman Spohn Corp. 

K. A. Vilminot, Black & Veatch 

A. L. Watkins, The Perry Nuclear Power Plant 

K. H. Wooten, ConocoPhillips Pipeline Co. 

W. J. Koves, Ex-Officio Member, UOP LLC 

A. P. Rangus, Ex-Officio Member, Bechtel 

C. J. Melo, Alternate, Worley Parsons 

A. Soni, Delegate, Engineers India Ltd. 



B31.9 BUILDING SERVICES PIPING SECTION COMMITTEE 



W. J. Sperko, Chair, Sperko Engineering Services, Inc. 

D. D. Christian, Vice Chair, Victaulic Co. 

S. Vasquez, Secretary, The American Society of Mechanical 

Engineers 
M. H. Barnes, Sebesta, Blomberg & Associates 
P. A. Bourquin, Consultant 
R. D. GiUigan, Retired 



L E. Hayden, Jr. Engineering Consultant 

L A. Loziuk, Piping Technology Construction, Inc. 

L D. MacNevin, Rehau, Inc. 

T. Q. McCawley, TQM Engineering 

F. R, Volgstadt, Volgstadt & Associates, Inc. 

J. W. Willis, Page Southerland Page, LLP 



B31 ADMINISTRATIVE COMMITTEE 



A. D. Nance, Chair, A. D. Nance Associates, inc. 

L E. Hayden, Jr. Vice Chair, Engineering Consultant 

P. D. Stumpf, Secretary, The American Society of Mechanical 

Engineers 
K. C. Bodenhamer, Enterprise Products Co. 
P. A. Bourquin, Retired 
P. D. Flenner, Flenner Engineering Services 
D. M. Fox, Oncor 

D. R. Frikken, Becht Engineering Co. 
R. R. Hoffmann, Federal Energy Regulatory Commission 



B. P. Holbrook, Babcock Power, inc. 

G. A. Jolly, Flowserve 

R. P. Merrill, Evapco, Inc. 

E. Michalopoulos, General Engineering and Commercial Co. 

R. G. Payne, Alstom Power, Inc. 

G. W. Spohn EH, Coleman Spohn Corp. 

R. B. West, State of Iowa, Division of Labor Services 

R. W. Haupt, Ex-Officio Member, Pressure Piping Engineering 

Associates, Inc. 
W. B. McGehee, Ex-Officio Member, Consultant 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME, 



B31 FABRICATION AND EXAMINATION COMMITTEE 



A. P. Rangus, Chair, Bechtel 

P. D. Stumpf, Secretory, The American Society of Mechanical 

Engineers 
J. P. EUenberger, Consultant 
R. J. Ferguson, Xaioy, Inc. 
D. J. Fet2ner, BP Exploration Alaska, inc. 
P. D. Flenner, Flenner Engineering Services 
W. W. Lewis, E. I. Du Pont 



S. P. Licud, Bechtel Power Corp. 

A. D. Nalbandian, Thielsch Engineering, inc. 

R. I. Seals, Consultant 

R. j. Silvia, Process Engineering & Constructors, Inc. 

W. J. Sperko, Sperko Engineering Services, inc. 

E. F. Summers, Jr., Babcock & Wilcox Construction Co. 

P. L. Vaughan, ONEOK Partners 



B31 MATERIALS TECHNICAL COMMITTEE 



M. L. Nayyar, Chair, Bechtel Power Corp. 

N. Lobe, Secretary, The American Society of Mechanical Engineers 

M. H. Barnes, Sebesta, Blomberg & Associates 

J. A. Cox, Lieberman Consulting LLC 

R. P. Deubler, Fronek Power Systems LLC 

P. j. Dobson, Cummins & Barnard, inc. 

W. H. Eskridge, Jr., Aker Kvaerner E & C 



R. A. Grichuk, Fluor Corp. 

C. L Henley, Black & Veatch 

D. W. Rahoi, Consultant 

R. A. Schmidt, Hackney Ladish, Inc. 
H. R. Simpson, IEA 

J. L. Smith, Jacobs Engineering Group 
2. DjilaU, Contributing Member, BEREP 



B31 MECHANICAL DESIGN TECHNICAL COMMITTEE 



W. }. Koves, Chair, U OP LLC 

G. A. Antaki, Vice Chair, Becht Nuclear Services 

T. Lazar, Secretary, The American Society of Mechanical Engineers 

C. Becht IV, Becht Engineering Co. 
j. P. Breen, Engineering Advisor 

J. P. EUenberger, Consultant 

D. J. Fetzner, BP Exploration Alaska, inc. 
J. A. Graziano, Tennessee Valley Authority 
J. D. Hart, SSD, inc. 

R. W. Haupt, Pressure Piping Engineering 
B. P. Holbrook, Babcock Power, Inc. 



6. Mayers, Alion Science & Technology 

T. Q. McCawley, TQM Engineering 

R. J. Medvick, Swage lok 

J. C. Minichiello, Areva 

T. j. O'Grady II, BP Exploration (Alaska) 

A. W. Paulin, Paulin Research Group 

R. A. Robleto, Consultant 

M. J. Rosenfeld, Kiefner & Associates, Inc. 

G. Stevick, Berkeley Engineering & Research, Inc. 

E. A. Wais, Wais and Associates, Inc. 

E. C. Rodabough, Honorary Member, Consultant 



B31 CONFERENCE GROUP 



T. A. Bell, Bonneville Power Administration 

G. Bynog, Texas Department of Labor and Standards 

R. A. Coomes, State of Kentucky, Department of Housing/Boiler 

Section 
D. H. Hanrath, North Carolina Department of Labor 

C. J. Harvey, Alabama Public Service Commission 

D. T. Jagger, Ohio Department of Commerce 
M. Kotb, Regie du Batiment du Quebec 

K. T. Lau, Alberta Boilers Safety Association 
R. G. Marini, New Hampshire Public Utilities Commission 
I. W. Mault, Manitoba Department of Labour 
A. W, fifletring, State of Indiana, Fire and Building Boiler and 
Pressure Vessel Division 



R. F. Mullaney, Boiler and Pressure Vessel Safety Branch 

P. Sher, State of Connecticut 

M. E. Skarda, State of Arkansas, Department of Labor 

D. A. Starr, Nebraska Department of Labor 

D. J. Stursma, Iowa Utilities Board 

R. P. Sullivan, The National Board of Boiler and Pressure Vessel 

Inspectors 
J. E. Troppman, Division of Labor/State of Colorado Boiler 

Inspections 
C. H. Walters, National Board of Boiler and Pressure Vessel 

Inspectors 
W. A. West, Lighthouse Assistance, inc. 
T. F. Wickham, Rhode Island Department of Labor 



B31 NATIONAL INTEREST REVIEW GROUP 



American Society of Heating, Refrigeration and Air Conditioning 

Engineers — H. R. Kornblum 
Chemical Manufacturers Association — D. R. Frikken 
Copper Development Association — A. Cohen 
Ductile Iron Pipe Research Association — T. F. Stroud 
Edison Electric Institute — R. L. Williams 
International District Heating Association — G. M. Von Bargen 



Manufacturers Standardization Society of the Valve and Fittings 

Industry — R. A. Schmidt 
National Association of Plumbing-Heating-Cooling Contractors — 

R. E. White 
National Certified Pipe Welding Bureau — j. Hansmann 
National Fire Protection Association — T. C. Lemoff 
Valve Manufacturers Association — R. A. Handschumacher 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



INTRODUCTION 



The ASME B31 Code for Pressure Piping consists of a number of individually published Sections, 
each an American National Standard. Hereafter, in this Introduction and in the text of this Code 
Section B31.9, where the word Code is used without specific identification, it means this Code 
Section. 

The Code sets forth engineering requirements deemed necessary for safe design and construction 
of pressure piping. While safety is the basic consideration, this factor alone will not necessarily 
govern the final specifications for any piping system. The designer is cautioned that the Code 
is not a design handbook; it does not do away with the need for the designer or for competent 
engineering judgment. 

To the greatest possible extent, Code requirements for design are stated in terms of basic design 
principles and formulas. These are supplemented as necessary with specific requirements to 
assure uniform application of principles and to guide selection and application of piping elements. 
The Code prohibits designs and practices known to be unsafe and contains warnings where 
caution, but not prohibition, is warranted. 

(a) This Code Section includes 

(1) references to acceptable material specifications and component standards, including 
dimensional requirements and pressure-temperature ratings 

(2) requirements for design of components and assemblies, including pipe supports 

(3) requirements and data for evaluation and limitation of stresses, reactions, and movements 
associated with pressure, temperature changes, and other forces 

(4) guidance and limitations on the selection and application of materials, components, and 
joining methods 

(5) requirements for the fabrication, assembly, and erection of piping 

(6) requirements for examination, inspection, and testing of piping 

It is intended that this Edition of Code Section B31.9 and any subsequent addenda not be 
retroactive. Unless agreement is specifically made between contracting parties to use another 
issue, or the regulatory body having jurisdiction imposes the use of another issue, the latest 
edition and addenda issued at least 6 months prior to the original contract date for the first phase 
of activity covering a piping system or systems shall be the governing document for all design, 
materials, fabrication, erection, examination, and testing for the piping until the completion of 
the work and initial operation. 

Users of this Code are cautioned against making use of revisions without assurance that they 
are acceptable to the proper authorities in the jurisdiction where the piping is to be installed. 

Code users will note that clauses in the Code are not necessarily numbered consecutively. Such 
discontinuities result from following a common outline, insofar as practicable, for all Code 
Sections. In this way, corresponding material is correspondingly numbered in most Code Sections, 
thus facilitating reference by those who have occasion to use more than one Section. 

The Code is under the direction of ASME Committee B31, Code for Pressure Piping, which is 
organized and operates under ASME procedures that have been accredited by the American 
National Standards Institute. The Committee is a continuing one and keeps all Code Sections 
current with new 7 developments in materials, construction, and industrial practice. Addenda may 
be issued periodically. New editions are published at intervals of 3 to 5 years. 

It is the owner's responsibility to select the Code Section that most nearly applies to a proposed 
piping installation. Different Code Sections may apply to different parts of an installation. Factors 
to be considered by the owner include: limitations of the Code Section, jurisdictional requirements, 
and the applicability of other codes and standards. All applicable requirements of the selected 
Code Section shall be met, and the owner should impose additional requirements supplementing 
those of the Code in order to assure safe piping for the proposed installation. 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



(b) Rules for each Code Section have been developed considering the need for application 
specific requirements for the pressure piping involved. Applications considered for each Code 
Section include 

(1) B31.1, Power Piping — piping typically found in electric power generating stations, indus- 
trial and institutional plants, geothermal heating systems, and central and district heating and 
cooling systems 

(2) B313, Process Piping — piping typically found in petroleum refineries; chemical, textile, 
paper, semiconductor, and cryogenic plants; and related processing plants and terminals 

(3) B31.4, Liquid Transportation Piping — piping for transporting predominantly liquid prod- 
ucts between plants and terminals and within terminals, and for pumping, regulating, and 
metering stations 

(4) B31.5, Refrigeration Piping — piping for refrigerants and secondary coolants 

(5) B31.8, Gas Transportation and Distribution Piping — piping for transporting predominantly 
gas products between sources and terminals, including compressor, regulating, and metering 
stations; and gas gathering pipelines 

(6) B31.9, Building Services Piping — piping for industrial, institutional, commercial, and 
public buildings, and multi-unit residences, which does not require the range of sizes, pressures, 
and temperatures covered in B31.1 

(7) B31.ll, Slurry Transportation Piping — piping for transporting aqueous slurries between 
plants and terminals, and within terminals and pumping and regulating stations. 

(c) Certain piping within a facility may be subject to other codes and standards, including but 
not limited to 

(1) ASME Boiler and Pressure Vessel Code, Section III — nuclear power piping 

(2) ANSI Z223.1, National Fuel Gas Code — fuel gas piping from the point of delivery to the 
connections of each gas utilization device 

(3) NFPA Fire Protection Standards — fire protection systems using water and other materials 
such as carbon dioxide, halon, foam, dry chemicals, and wet chemicals 

(4) NFPA 99 Health Care Facilities — medical and laboratory gas systems 

(5) NFPA 8503, Standard for Pulverized Fuel Systems. Building and Plumbing Codes. 

The Committee has established an orderly procedure to consider requests for interpretation 
and revision of Code requirements. To receive consideration, inquiries must be in writing and 
must give full particulars (see Mandatory Appendix IV, Preparation of Technical Inquiries). The 
approved reply to an inquiry will be sent directly to the inquirer. In addition, the question and 
reply will be published as part of an Interpretation Supplement issued to the applicable Code 
Section. 

A Case is the prescribed form of reply to an inquiry when study indicates that the Code wording 
needs clarification or when the reply modifies existing requirements of the Code or grants 
permission to use new materials or alternative constructions. Proposed Cases are published in 
Mechanical Engineering for public review. In addition, the Case will be published as part of a Case 
Supplement issued to the applicable Code Section. 

A Case is normally issued for a limited period, after which it may be renewed, incorporated 
in the Code, or allowed to expire if there is no indication of further need for the requirements 
covered by the Case. However, the provisions of a Case may be used after its expiration or 
withdrawal, provided the Case was effective on the original contract date or was adopted before 
completion of the work, and the contracting parties agree to its use. 

Materials are listed in the Stress Tables only when sufficient usage in piping within the scope 
of the Code has been shown. Materials may be covered by a Case. Requests for listing shall 
include evidence of satisfactory usage and specific data to permit establishment of allowable 
stresses, maximum and minimum temperature limits, and other restrictions. (To develop usage 
and gain experience, unlisted materials may be used in accordance with para. 923.1.2.) 

Requests for interpretation and suggestions for revision should be addressed to the Secretary, 
ASME B31 Committee, Three Park Avenue, New York, NY 10016-5990. 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



ASME B31.9-2008 
SUMMARY OF CHANGES 



Following approval by the B31 Committee and ASME, and after public review, ASME B31. 9-2008 
was approved by the American National Standards Institute on April 1, 2008. 

ASME B31. 9-2008 includes editorial changes, revisions, and corrections identified by a margin 
note, (08), placed next to the affected area. 

Change 

Revised 

Revised 

Revised 

Fig. 900.1.2B redesignated as Fig. 900.1.2 

Title revised 

Table 904.2. 1A redesignated as 
Table 904.2.1 

For eq. (8), nomenclature for L, U f and Y 
added 

Fig. 921.1.3C redesignated as 
Fig. 921.1.3-1 

Fig. 921.1. 3D redesignated as 
Fig. 921.1.3-2 

Table 921.2.2A redesignated as 
Table 921.2.2 

(1) MSS SP-84 deleted 

(2) MSS SP-110 added 

(3) ASTM F 2080 added 

(4) Note (2) added 

33 Table 926.2 ASTM B 828 added 

35 Fig. 927.4.3-1 Fig. 927.4.3A redesignated as 

Fig. 927.4.3-1 

36 Fig. 927.4.3-2 Fig. 927.4.3B redesignated as 

Fig. 927.4.3-2 

Fig. 927.4.3-3 Fig. 927.4.3C redesignated as 

Fig. 927.4.3-3 

37 Fig. 927.4.5-1 Fig. 927.4.5A redesignated as 

Fig. 927.4.5-1 

Fig. 927.4.5-2 Fig. 927.4.5B redesignated as 

Fig. 927.4.5-2 

38 Fig. 927.4.6-1 Fig. 927.4.6A redesignated as 

Fig. 927.4.6-1 

Fig. 927.4.6-2 Fig. 927.4.6B redesignated as 

Fig. 927.4.6-2 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



Page 


Location 


1 


900.1.2(c)(1) 




900.1.2(c)(2) 




900.1.2(c)(6) 


2 


Fig. 900.1.2 


3 


900.2 


12 


Table 904.2.1 


17, 18 


914.4.1(a)(2) 


21 


Fig. 921.1.3-1 


22 


Fig. 921.1.3-2 


23 


Table 921,2.2 


30-32 


Table 926.1 



Page 
39 
40 
58, 59 

63-66 
67-71 



Location 

927.6.3 

928.2.2 

Mandatory Appendix III 



Change 

Sixth sentence revised 

Revised 

(1) ASTM B 828 reference added 

(2) ASTM F 2080 reference added 

(3) MSS SP-110 reference added 



Nonmandatory Appendix B Added 
Index Updated 



SPECIAL NOTE: 

The Interpretations to ASME B31.9 are included in this edition as a separate section for the user's 



convenience. 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME, 



INTENTIONALLY LEFT BLANK 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



ASME B31.9-2008 



BUILDING SERVICES PIPING 

Chapter 1 
Scope and Definitions 



900 GENERAL 

This Building Services Piping Code is a Section of 
The American Society of Mechanical Engineers Code 
for Pressure Piping, B31. This Section, herein called the 
Code, is published as a separate document for conve- 
nience. 

Standards and specifications incorporated by refer- 
ence in this Code are shown in Table 926.1, Mandatory 
Appendix I, and elsewhere. It is not considered practical 
to refer to a dated edition of each standard or specifica- 
tion where referenced. Instead, the dated edition refer- 
ences are included in Mandatory Appendix III. 

The user is cautioned that the local building code must 
be observed and adhered to when its requirements are 
more stringent than those of this Code. 

Components of piping systems shall conform to the 
specifications and standards listed in this Code. Piping 
elements neither specifically approved nor specifically 
prohibited by this Code may be used provided they are 
qualified for use as set forth in applicable chapters of 
this Code. 

Engineering requirements of this Code, while consid- 
ered necessary and adequate for safe design, generally 
employ a simplified approach. An engineer capable of 
applying a more rigorous analysis shall have the latitude 
to do so. He must be able to demonstrate the validity 
of his approach. 

900.1 Scope 

900.1.1 Coverage and Application. This Code 
Section has rules for the piping in industrial, institu- 
tional, commercial, and public buildings, and multi-unit 
residences, which does not require the range of sizes, 
pressures, and temperatures covered in B31.1. This Code 
prescribes requirements for the design, materials, fabri- 
cation, installation, inspection, examination, and testing 
of piping systems for building services. It includes pip- 
ing systems in the building or within the property limits. 

900.1.2 Services and Limits 

(a) Services. This Code applies to the following build- 
ing services, except as excluded in para. 900.1.3: 



(1) water and antifreeze solutions for heating and 
cooling 

(2) condensing water 

(3) steam or other condensate 

(4) other nontoxic liquids 

(5) steam 

(6) vacuum 

(7) compressed air 

(8) other nontoxic, nonflammable gases 

(9) combustible liquids including fuel oil 

(b) Boiler External Piping. The scope of this Code 
includes boiler external piping within the following 
limits: 

(1) for steam boilers, 15 psig (103 kPa gage) max. 

(2) for water heating units, 160 psig (1 103 kPa 
gage) max. and 250°F (121°C) max. 

Boiler external piping above these pressure or temper- 
ature limits is within the scope of ASME B31.1. Boiler 
external piping is the piping connected to the boiler and 
extending to the points identified in Fig. 900.1.2. 

(c) Material and Size Limits. Piping systems of the fol- 
lowing materials are within the scope of this Code, 
through the indicated maximum size (and wall thickness 
if noted): 

(1) carbon steel: NPS 48 (DN 1 200) and 0.50 in. 
(12.7 mm) wall 

(2) stainless steel: NPS 24 (DN 600) and 0.50 in. 
(12.7 mm) wall 

(3) aluminum: NPS 12 (DN 300) 

(4) brass and copper: NPS 12 (DN 300) and 
12.125 in. (308 mm) O.D. for copper tubing 

(5) thermoplastics: NFS 24 (DN 600) 

(6) ductile iron: NFS 48 (DN 1 200) 

(7) reinforced thermosetting resin: 24 in. (600 mm) 
nominal 

Other materials may be used as noted in Chapter III. 

(d) Pressure Limits. Piping systems with working 
pressures not in excess of the following limits are within 
the scope of this Code: 

(1) steam and condensate: 150 psig (1 034 kPa g) 

(2) liquids: 350 psig (2 413 kPa g) ' 

(3) vacuum: 1 arm external pressure 



(08) 



(08) 



(08) 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



ASME B31.9-2008 



(08) 



Fig. 900.1.2 Code Jurisdictional Limits for Piping — Drum Type Boilers 



Vents and 
instrumentation 



Single installation 

Multiple installation 

Common headeri 

x 
Saturated drain 

Control device 



Hot reheat 



Cold reheat 




Level indicators 

Surface blow 
Continuous 

blow 
Chemical feed 
„ drum sample 

-- Soot blowers 

-- Single installation 

r-f Soot blowers 



i Multiple installations 



i/1o Single boiler 

Regulating valve 

Two or more 
-- boilers fed from 
a common source 



Biow-off 
single and multiple 
installations 



.Regulating valve 



Two or more 



boilers fed 
from a common 
source 



£XMX3>-- 



Admintstrative Jurisdiction and Technical Responsibility 

Boiler Proper — The ASME Boiler and Pressure Vessel Code (ASME BPVC) has total administrative jurisdiction and 

technical responsibility. Refer to ASME BPVC Section I, Introduction, fourth paragraph. 

e Boiler External Piping and Joint (BEP). See para. 900.1.2(b) for B31.9 Scope. 

o Nonboiler External Piping and Joint (NBEP), 



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ASME B31.9-2008 



(4) compressed air and gas: 150 psig (1 034 kPa g) 
(e) Temperature Limits, Piping systems with working 
temperatures not in excess of the following limits are 
within the scope of this Code: 

(1) steam and condensate: 366°F (1S6°C) 

(2) other gases and vapors: 200°F (93°C) 

(3) other nonflammable liquids: 250°F (121°C) 
The minimum temperature for all services is 0°F 

(-18°C). 

900.1.3 Exclusions. This Code does not apply to 
economizers, heaters, pumps, tanks, heat exchangers, 
and equipment covered by the ASME Boiler and 
Pressure Vessel (BPV) Code. 

(08) 900.2 Terms and Definitions 

adhesive bond: a union of materials by means of an 
adhesive. 

anchor: a structural attachment device or mechanism that 
prevents the movement of pipe due to thermal expan- 
sion, expansion joint thrust, and other loads. 

arc welding: a group of welding processes that produce 
coalescence of metals by heating them with an arc, with 
or without the use of filler metal, 

assembly: the joining together of two or more piping 
components. 

automatic welding: welding with equipment that per- 
forms the welding operation without constant observa- 
tion and adjustment of controls by a welding operator. 
The equipment may or may not perform the loading 
and unloading of the work. 

backing: material placed at the root of a weld joint to 
support molten weld metal. 

backing ring: backing in the form of a ring. 

ball or swivel joint: a joint that permits pipe motion by 
means of rotation. 

base metal (material): the metal (material) to be welded, 
brazed, soldered, or cut. 

boiler external piping (BEP): See para. 900.1.2(b). 

branch connection: the attachment of the end of a branch 
pipe to the run of a main pipe, with or without the use 
of a fitting. Figure 927.4.6 shows typical branch connec- 
tions which do not use fittings. 

braze welding: a joining process that produces coalescence 
of metals by using a filler metal whose liquidus is above 
800°F (427°C) and below the solidus of the base metals. 
Unlike brazing, the filler metal is not distributed in the 
joint by capillary attraction. 

brazing: a joining process that produces coalescence of 
metals by heating to a suitable temperature and by using 
a filler metal whose liquidus is above 800°F (427°C) and 
below the solidus of the base metals. The filler metal is 



distributed by capillary attraction between closely fitted 
joint surfaces. 

brine: a liquid used for the transmission of heat without 
change of state in cooling systems, which is nonflamma- 
ble or has a flash point above 1 50°F (66°C) as determined 
by the method of ASTM D 93. 

brittle failure: a pipe failure mode that exhibits no mate- 
rial deformation visible to the naked eye, i.e., stretching, 
elongation, or necking down, in the area of the break. 

butt joint: a joint between two members aligned approxi- 
mately in the same plane. 

chilled water: water or an antifreeze solution used as a 
brine at a supply temperature below 60°F (1.6°C). 

coalescence: the growing together or growth into one 
body of materials being welded, brazed, or soldered. 

combustible liquid: a liquid having a flash point at or 
above 100°F (38°C). 

consumable insert: backing in the form of filler metal 
which is melted into the root of the weld and fused with 
the base metals. 

contractor: the entity responsible for fabrication and 
installation of piping and associated equipment. 

crack: a fracture-type imperfection characterized by a 
sharp tip and high ratio of length and depth to opening 
displacement. 

DN: metric designated pipe size. The number is the 
millimeter approximation of the inch pipe size using 
one inch equal to 25 mm. The pipe is still manufactured 
in inch sizes. 

defect: an imperfection which by nature or accumulated 
effect renders a part of the piping unable to meet mini- 
mum applicable acceptance standards or specifications. 
A defect is cause for rejection. 

deposited metal: filler metal that has been added during 
a welding operation. 

design pressure: the pressure, equal to or greater than 
the highest working pressure, used to determine the 
minimum permissible wall thickness or component rat- 
ing. See para. 901.2, 

design temperature: the temperature equal to or higher 
than the highest working temperature, used in 
determining the required wall thickness or component 
rating. See para. 901.3. 

design thickness: the sum of the minimum thicknesses 
required by the design conditions and corrosion, 
mechanical, and other allowances. 

employer: the owner, manufacturer, fabricator, contractor, 
assembler, or installer responsible for the welding, braz- 
ing, and NDE performed by his organization, including 
procedure and performance qualifications. 



Copyright © 2008 by the American Society of Mechanical Engineers. 
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ASME B31.9-2008 



engineer: the engineer as agent of the owner is the party 
responsible for design of piping systems to meet 
operating and safety standards. 

engineering design: the detailed design for a piping instal- 
lation, developed from the building systems require- 
ments and conforming to Code requirements, including 
necessary drawings and specifications. 

equipment connection: an integral part of equipment such 
as boilers, pressure vessels, heat exchangers, pumps, 
etc., designed for attachment of piping. 

erection: the complete installation of a piping system, 
including field fabrication and assembly. 

examination: any of a number of quality control opera- 
tions that use visual or other methods to reveal imperfec- 
tions (indications) and to evaluate their significance. 

examiner: a person employed by the piping manufac- 
turer, fabricator, or erector who is competent to perform 
examinations. 

expansion joint: a component installed in a piping system 
for the purpose of absorbing dimensional changes, such 
as those caused by thermal expansion or contraction. 

fabrication: bending, forming, cutting, machining, and 
joining of piping components into integral subassem- 
blies ready for erection. Fabrication may be performed 
in the shop or in the field. 

face of weld: the exposed surface of a weld on the side 
from which the welding was done. 

filler metal (material): metal (material) to be added in 
welding, brazing, braze welding, or soldering. 

fillet weld: a weld of approximately triangular cross sec- 
tion joining two surfaces approximately at right angles. 

flammable liquid: a liquid having a closed cup flash point 
below 100°F (38°C). 

flux: material used to dissolve, to prevent accumulation 
of, or to facilitate removal of oxides and other undesir- 
able substances during welding, brazing, or soldering. 

flux-cored arc welding (FCAW): an arc welding process 
that employs a continuous tubular filler metal (consum- 
able) electrode having a core of flux for shielding. Added 
shielding may or may not be obtained from an externally 
supplied gas or gas mixture. 

full fillet weld: a fillet weld whose size is equal to the 
thickness of the thinner member joined. See size of weld. 

fusion: the melting together of filler and base material, 
or of base material only, that results in coalescence. 

gas metal arc welding (GMAW): an arc welding process 
that employs a continuous solid filler metal (consum- 
able) electrode. Shielding is obtained entirely from an 
externally supplied gas or gas mixture. (Some methods 
of this process have been called MIG or C0 2 welding.) 

gas pocket: See porosity, the preferred term. 



gas tungsten arc welding (GTAW): an. arc welding process 
that employs a tungsten (nonconsumable) electrode. 
Shielding is obtained from a gas or gas mixture. Pressure 
may or may not be used and filler metal may or may 
not be used. (This process has sometimes been called 
TIG welding.) 

gas welding: See oxyfuel gas welding. 

groove weld: a weld made in the groove between two 
members. 

header: See main. 

heat affected zone (HAZ): that portion of the base metal 
which has not been melted, but whose mechanical prop- 
erties or microstructure have been altered by the heat 
of welding, brazing, soldering, forming, or cutting. 

heat fusion: a joining process in which melted surfaces 
of plastic pipe and fittings are engaged and held together 
under moderate pressure until cool. 

imperfection: an abnormality or indication found during 
examination or inspection that is not necessarily a cause 
for rejection. See also defect. 

inert gas: a gas that does not combine with or affect the 
base material or filler material. 

inert gas metal arc welding: See gas metal arc welding, the 
preferred term. 

inspection: any operation performed to assure the owner 
that the materials, components, fabrication, and installa- 
tion are in accordance with the engineering design. 
Inspection may include review of certifications, welding 
procedure and welder qualifications, records of exami- 
nations and testing, and any examination that may be 
required by the engineering design. 

inspector: the owner, or a person representing the owner 
(not employed by the manufacturer, fabricator, or erector 
when different from the owner) who performs an 
inspection. 

joint design: the joint geometry together with the required 
dimensions. 

joint penetration: the minimum depth a groove w T eld 
extends from its face into a joint, exclusive of reinforce- 
ment. Joint penetration may include root penetration. 
See root penetration. 

liquidus: the lowest temperature at which a metal or 
alloy is completely liquid. 

main: as used in this Code, a section of pipe to which a 
branch or branches are connected. 

manual welding: welding wherein the entire welding 
operation" is performed and controlled by hand. 

maximum allowable stress: the maximum stress value that 
may be used in the design formulas for a given material 
and design temperature. Stress values tabulated in Man- 
datory Appendix I are for stress in tension. 



Copyright © 2008 by the American Society of Mechanical Engineers. 
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ASME B31.9-2008 



may: As used in this Code, denotes permission or indif- 
ference; it is neither a requirement nor a recommen- 
dation. 

■mechanical joint: a pipe joint in which mechanical 
strength is developed by threaded, grooved, rolled, com- 
pressed, flared, or flanged pipe ends, with gasketed, 
caulked, or machined and mated surfaces for leak 
resistance. 

melting range: the temperature range between solidus 
and liquidus of a metal. 

miter joint: two or more straight sections of pipe joined 
(in pairs) on a. line bisecting the angle of junction so as 
to produce a change in direction. 

nominal: a dimension of a product as given in a standard 
or specification, prior to consideration of tolerances; 
also, a designated size or rating, not necessarily an actual 
measurement. 

nominal thickness: the thickness given in the product spec- 
ification to which manufacturing tolerances are applied. 

NFS: nominal pipe size. 

oxidizing flame: an oxyfuel gas flame having an oxidizing 
effect due to excess oxygen. 

oxy 'acetylene welding (OAW): a gas welding process in 
which coalescence is produced by heating with a gas 
flame or flames obtained from the combustion of acety- 
lene with oxygen, with or without the application of 
pressure and with or without the use of filler metal. 

oxyfuel gas welding (OFW): a group of welding processes 
in which coalescence is produced by heating with a 
flame or flames obtained from the combustion of fuel 
gas with oxygen, with or without the application of 
pressure, and with or without the use of filler metal. 

oxygen cutting (OC): a group of cutting processes used 
to sever or remove metals by means of the reaction of 
oxygen with the base metal at elevated temperatures. 
In the case of oxidation-resistant metals the reaction is 
facilitated by use of a chemical flux or metal powder. 

pass: a single progression of a welding or surfacing oper- 
ation along a joint, weld deposit, or substrate. The result 
of a pass is a weld bead/ layer, or spray deposit. 

peel test: a destructive method of examination that 
mechanically separates a lap joint by peeling. 

peening: the mechanical working of metals using impact 
blows. 

pipe: a pressure-tight cylinder used to convey a fluid or 
a fluid pressure, ordinarily designated pipe in applicable 
material specifications. Materials designated tube or tub- 
ing in the specifications are treated as pipe when 
intended for pressure service. 

pipe alignment guide: a restraint in the form of a sleeve 
or frame that permits the pipeline to move freely only 
along the axis of the pipe. See restraint. 



pipe-supporting elements: These include: 

fixtures: elements that transfer the load from the pipe 
or structural attachment to the support structure or 
equipment. 

structural attachments: brackets, clips, lugs, or other 
elements welded, bolted, or clamped to the pipe. Sup- 
port structures such as stanchions, towers, building 
frames, and foundations, and equipment such as vessels, 
exchangers, and pumps, are not considered pipe- 
supporting elements. 

piping: assemblies of pipe and piping components used 
to convey, distribute, mix, separate, discharge, meter, 
and control fluid flows. Piping also includes pipe- 
supporting elements, but does not include support struc- 
tures, such as building frames, bents, foundations, or 
any equipment excluded from this Code. 

piping components: mechanical elements suitable for join- 
ing or assembly of pipe into pressure-tight fluid con- 
taining piping systems. Components include fittings, 
flanges, gaskets, bolting, valves, and devices such as 
expansion joints, flexible joints, pressure hoses, traps, 
strainers, in-line portions of instruments, and separators. 

piping system: interconnected piping subject to the same 
set or sets of design conditions. 

porosity: cavity-type imperfections formed by gas entrap- 
ment during solidification of weld metal. 

postheating, also called postweld heat treatment (PWHT): 
the application of heat to an assembly after a welding, 
brazing, soldering, cutting, or forming operation. 

preheating (PH): the application of heat to the base metal 
immediately before welding, brazing, soldering, cutting, 
or forming. 

procedure: the detailed elements (with prescribed values 
or range of values) of a process or method used to pro- 
duce a specific result. 

procedure qualification: the demonstration that welds or 
other w 7 ork produced by a specified procedure can meet 
prescribed standards. 

purge gas: the replacement of air within a piping system 
with an inert gas; may be required by the welding proce- 
dure specification prior to making a gas tungsten arc 
weld. 

qualification: See preferred terms, procedure qualification 
and welder performance qualification. 

recommend: has the same effect as should. 

reducing flame: an oxyfuel gas flame having a reduced 
effect due to excess fuel gas. 

reinforcement: In branch connections, reinforcement is 
material around a branch opening that serves to 
strengthen it. The material is either integral in the branch 
components or added in the form of weld metal, a pad, 
a saddle, or a sleeve. In welding, reinforcement is weld 



Copyright © 2008 by the American Society of Mechanical Engineers. <£^ s . 

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ASME B31.9-2008 



metal in excess of the specified weld size. 

restraint: a structural attachment, device, or mechanism 
that limits movement of the pipe in one or more direc- 
tions. See pipe alignment guide. 

reverse polarity: the arrangement of direct current arc 
welding leads with the work as the negative pole and 
the electrode as the positive pole of the welding arc; a 
synonym for direct current electrode positive. 

root opening: the separation between members to be 
joined at the root of the joint. 

root penetration: the depth that a weld extends into the 
root of a joint measured on the center line of the root 
cross section. 

root reinforcement: weld reinforcement at the side other 
than that from which welding was done. 

root surface: the exposed surface of a weld on the side 
other than that from which welding was done. 

run: See main. 

seal weld: a fillet weld used on a pipe joint primarily to 
obtain fluid tightness as opposed to mechanical 
strength; usually used in conjunction with a threaded 
joint. 

semiautomatic arc welding: arc welding with equipment 
that controls only the filler metal feed. The advance of 
the welding is manually controlled. 

shall: used to indicate that a provision or prohibition in 
this Code is required, i.e., mandatory. 

shielded metal arc welding (SMAW): an arc welding process 
in which coalescence is produced by heating with an 
electric arc between a covered metal electrode and the 
work. Shielding is obtained from decomposition of the 
electrode covering. Pressure is not used and filler metal 
is obtained from the electrode. 

should: used to indicate that a provision of this Code is 
not required, but represents good practice. 

single-welded butt joint: a butt joint welded from one 
side only, 

size of weld 

groove weld: the joint penetration (depth of bevel plus 
root penetration when specified). The size of a groove 
weld and its effective throat are the same. 

fillet weld: for an equal leg fillet weld, the leg length of 
the largest isosceles right triangle which can be inscribed 
within the fillet weld cross section. For an unequal leg 
fillet weld, the leg lengths of the largest right triangle 
which can be inscribed within the fillet w 7 eld cross 
section. 

NOTE: When one m ember makes an angle with the other member 
greater than 105 deg, the leg length (size) is of less significance 
than the effective throat, which is the controlling factor in the 
strength of the weld. 



slag inclusion: nonmetallic solid material trapped in the 
weld metal or between the weld metal and base metal 

solder: a filler metal used in soldering which has a liq- 
uidus not exceeding 800°F (427°C). 

soldering: a group of joining processes that produces 
coalescence of metals by heating them to a suitable tem- 
perature and by using a filler metal having a liquidus 
not exceeding 800°F (427°C) and below the solidus of 
the base metals. 

solidus: the highest temperature at which a metal or alloy 
is completely solid. 

solvent cement: a solvent adhesive that dissolves or soft- 
ens the surface being bonded so that the assembly 
becomes essentially a single fused piece. 

solvent cementing: joining plastic parts by use of the 
appropriate solvent cement. 

spacer strip: a metal strip or bar prepared for a groove 
weld, and inserted in the root of a joint to serve as a 
backing and to maintain root opening during welding; 
it can also bridge an exceptionally wide gap due to poor 
fit- up. 

spatter: in arc and gas welding, the metal particles 
expelled during welding that do not form part of the 
weld. 

straight polarity: the arrangement of direct current arc 
welding leads in which the work is the positive pole 
and the electrode is the negative pole of the welding 
arc; a synonym for direct current electrode negative. 

stringer head: a type of weld bead made without apprecia- 
ble weaving motion. See also weave bead. 

submerged arc welding (SAW): an arc welding process that 
produces coalescence of metals by heating them with 
an arc or arcs drawn between a bare metal electrode or 
electrodes and the base metals. The arc is shielded by 
a blanket of granular fusible material. Pressure is not 
used and filler metal is obtained from the electrode and 
sometimes from a supplementary welding rod. 

supplemental steel: structural members that frame 
between existing building framing steel members and 
are significantly smaller in size than the existing steel. 

tack weld: a weld made to hold parts in proper alignment 
until final welds are made. 

thermoplastic: a plastic that is capable of being repeatedly 
softened by heating and hardened by cooling, and 
whose change upon heating is substantially physical. 

thermosetting resin: a plastic that, when cured by heat or 
chemical means, changes into a substantially infusible, 
insoluble product. 

throat of a fillet weld 

actual: the shortest distance from the root of a fillet 
weld to its face. 



Copyright © 2008 by the American Society of Mechanical Engineers. ^ 

No reproduction may be made of this material without written consent of ASME. ^S 



ASME B31.9-2008 



theoretical: the perpendicular distance from the begin- 
ning of the root of the joint to the hypotenuse of the 
largest right triangle that can be inscribed within the 
fillet weld cross section. 

thrust block: a type of anchor consisting of a concrete 
block bearing against earth, usually used on an under- 
ground pipeline. 

toe of weld: the junction between the face of a weld and 
the base metal. 

tungsten electrode: a nonconsumable electrode used in 
arc welding, consisting of a tungsten wire. 

undercut: a groove melted into the base metal adjacent 
to the toe or root of a. weld, and left unfilled by weld 
metal. 

weave head: a type of weld bead made with transverse 
oscillation. 

welder: one who is capable of performing a manual or 
semiautomatic welding operation. 

welder certification: the action of determining, verifying, 
or attesting in writing that a welder is qualified to pro- 
duce welds which can meet prescribed standards. 

Welder Performance Qualification: demonstration of a 
welder's ability to produce welds in a manner described 
in a welding procedure specification that meets pre- 
scribed standards. 

welding: a process in which a localized coalescence of 
metal is produced by heating to a suitable temperature, 
with or without pressure and with or without the use 
of filler metal. The filler metal has a melting point 
approximately the same as the base metals. 

welding operator: one who operates a welding machine 
or automatic welding equipment. 

ivelding procedure: the detailed methods and practices, 
including all joint welding procedures, involved in mak- 
ing a welded joint. 

Welding Procedure Qualification: demonstration that 
welds made in a manner described in the Welding Proce- 
dure Specification will meet prescribed standards. The 
Procedure Qualification Record (PQR) describes the 
materials, methods, and results of the test. 

Welding Procedure Specification (WPS): the written form 
of the welding procedure for making a specified kind 
of a welded joint using specified base and filler metals. 

wetting: the condition in which a liquid filler metal or 
flux forms a zero angle of contact on a solid base metal 
surface. 

9003 Nomenclature 

Symbols used in this Code are listed here with defini- 
tions. Upper and lower case English letters precede 
Greek letter symbols. 



A - thickness allowance for corrosion (see para. 
902.4.1), for mechanical joint preparation (see 
para. 902.4.2), or for mechanical strength (see 
para. 902.4.4), in. (mm) 

a = weld size (attachment weld, back of slip-on or 
socket welding flange), in. (mm) 

B = internal area, greatest of pipe or expansion joint 
bellows, in. 2 (m 2 ) 

b — weld size (attachment weld, face of slip-on 
flange), in. (mm) 

C = head or closure factor, dimensionless 

d = inside pipe diameter (D - 2T), for use in closure 
and branch connection reinforcement calcula- 
tions, in. 
d^ = inside diameter of gasket on raised or flat 
(plain) face flanges; or gasket pitch diameter 
for ring joint and fully retained gasketed 
flanges, in. (mm) 

D = outside pipe diameter, as measured or per 

dimensional standard, in. (mm) 
D n = diameter equal to nominal pipe size, in. (mm) 

e = coefficient of thermal expansion, in/in. /°F 
(mm/m/°C) 

E — longitudinal or spiral wielded joint efficiency 
factor, dimensionless (Table 902.4.3) 
E m — modulus of elasticity, psi (kPa) (Table 919.3.1) 

f = stress range reduction factor for cyclic condi- 
tions, dimensionless 

F = casting quality factor, dimensionless 

h = thread depth in ASME Bl.20.1, in. (mm) 

1 = moment of inertia, in. 4 (mm 4 ) 
ksi = kips (1000 lb) per sq in. (MPa) 

L = developed length of pipe axis between 

anchors, ft (m) 
L s = length of pipe between supports or guides, ft 
(m) 

N = number of stress or thermal cycles, dimen- 
sionless 

P = internal design pressure, psig (kPa) 

Q — force to overcome spring rate or friction of 
expansion joint and guides, pounds-force 
(lb/ft) (N/mm) 

r 2 = mean radius of pipe, based on nominal 
dimensions, in. (mm) 

R — anchor or support reaction, Ibf (N) 
Rj — effective radius of miter joint; the shortest dis- 
tance from the pipe center line to the intersec- 
tion of planes of adjacent miter joints, in, (mm) 

S = basic allowable stress value prior to applying 
joint factor £, psi (kPa) 
S A = allowable stress range, psi (kPa) [see para. 
902.3.2(c)] 

S c = basic material allowable stress prior to 
applying joint factor E, at minimum (cold) nor- 
mal temperature, psi (kPa) 
S E = computed expansion stress range, psi (kPa) 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



ASME B31.9-2008 



s f = 



s h 



Si 
SE 



tr = 



*-n; — 



maximum allowable stress in material due to 
internal pressure considering casting quality 
factor at design temperature, psi (kPa) 
basic material allowable stress prior to 
applying joint factor E, at maximum (hot) nor- 
mal temperature, psi (kPa) 
longitudinal compressive stress, psi (kPa) 
longitudinal stress due to pressure, psi (kPa) 
maximum allowable stress in material due to 
internal pressure, considering joint efficiency 
factor E at design temperature, psi (kPa) 
minimum required thickness of flat head, clo- 
sure, or blank, in. (mm) 

minimum required wall thickness, in. (mm) 
(see para. 904.1.1) 



T 



T-n 

U 

v 
Y 



AT 



weld throat size, in. (mm) 
measured or minimum specification wall 
thickness, exclusive of corrosion allowance, 
in. (mm) 

nominal pipe thickness, in. (mm) 
distance between anchors, measured in a 
straight line, ft (m) 
Poisson's ratio, dimensionless 
resultant thermal movement to be absorbed by 
piping system, in. (mm) 
lesser angle between axis of branch and axis 
of main, deg 

temperature difference, °F (°C) 
angle of miter cut (one-half the change in direc- 
tion at a miter joint), deg 



8 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of AS'ME. 



ASME B31.9-2008 



Chapter II 
Design 



PARTI 
CONDITIONS AND CRITERIA 

901 DESIGN CONDITIONS 

901.1 General 

These design conditions define the pressures, temper- 
atures, and other conditions applicable to the design of 
building services piping. Such systems shall be designed 
for the most severe conditions of coincident pressure, 
temperature, and loading anticipated under any condi- 
tions of normal operation, including startup and shut- 
down. The most severe condition shall be that which 
results in the greatest required wall thickness and the 
highest component rating. 

901.2 Pressure 

Pressures referred to in this Code are expressed in 
pounds-force per square inch gage (psig), unless other- 
wise stated. 

901.2.1 Internal Design Pressure. The internal 
design pressure, including the effects of static head, shall 
not be less than the maximum sustained fluid operating 
pressure within the piping system. Consideration 
should be given to possible pressure surges. Pump shut- 
off pressures shall be considered. 

901.2.2 External Design Pressure. Piping subject to 
external pressure shall be designed for the maximum 
differential pressure anticipated in normal operation. 

901.23 Required Containment or Relief. Provision 
shall be made to safely contain or relieve excessive pres- 
sure to which the piping may be subjected. Piping not 
protected by a pressure-relieving device, or that can 
be isolated from a pressure-relieving device shall be 
designed for at least the highest pressure that can be 
developed. 

901.3 Temperature 

Temperatures referred to in this Code are the tempera- 
tures of piping materials expressed in degrees Fahren- 
heit, unless otherwise stated. The piping shall be 
designed for a temperature representing the maximum 
condition expected. 

The temperature of the piping materials is considered 
to be the same as that of the fluid in the piping. 



901.4 Ambient influences 

901.4.1 Cooling, Effects on Pressure. Where the 
cooling of a fluid may reduce the pressure in the piping 
to below atmospheric, the piping shall be designed to 
withstand the external pressure, or provision shall be 
made to break the vacuum. 

901.4.2 Fluid Expansion Effects. Where the expan- 
sion of a fluid may increase the pressure, the piping 
system shall be designed to withstand the increased 
pressure, or provision shall be made to relieve the excess 
pressure. 

901.5 Dynamic Effects 

(a) General Piping shall be designed, arranged, and 
supported with due consideration of vibration, hydrau- 
lic shock, wind, and earthquake. 

(b) Seismic Analysis. Seismic analysis and design for 
pipe supports and related structures shall be in accor- 
dance with the requirements of the governing building 
code for the jurisdiction in which the work is being 
performed. 

901.7 Thermal Expansion and Contraction Loads 

When a piping system is prevented from free thermal 
expansion and contraction as a result of anchors and 
restraints, thrusts and moments are set up that must be 
taken into account as set forth in paras. 902 and 919. 

902 DESIGN CRITERIA 

902.1 General 

The provisions of para. 902 pertain to ratings, stress 
values, allowable stress criteria, design allowances, and 
minimum design values, and formulate the permissible 
variations in these factors when used in design of piping. 

902.2 Pressure-Temperature Design Criteria for 
Piping Components 

902.2.1 Components Having Specific Ratings 

(a) For Listed Components. Pressure-temperature rat- 
ings have been established for certain piping compo- 
nents and are contained in some of the standards listed 
in Table 926.1. These ratings are accepted for use in 
accordance with this Code, 

(b) For Components Not Listed. If it is necessary to use 
components that do not conform to standards listed in 
Table 926.1, they shall be qualified for pressure design 



Copyright © 2008 by the American Society of Mechanical Engineers. 
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ASME B31.9-2008 



in accordance with the requirements of para. 904. In 
addition, they shall be used within the ratings and other 
service limitations given by the manufacturer. 

902.2.2 Components Not Having Specific Ratings. 

Components conforming to some of the standards listed 
in Table 926.1 are specified as having ratings equal to 
those of seamless pipe of corresponding material and 
wall thickness. For the purposes of this Code, these 
components shall be used as follows: 

(a) Butt welding fittings shall be specified to a wall 
thickness at least as great as that of the pipe to which 
they are to be connected. 

(b) Forged steel or alloy threaded and butt welding 
fittings shall be specified in the nominal pressure class 
at least as great as that listed for the wall thickness of 
pipe to which they are to be connected. 

902.2.3 Ratings, Normal Design Conditions. A pip- 
ing system shall be considered safe for operation if the 
maximum pressure that may act on any part or compo- 
nent of the system does not exceed the maximum pres- 
sure allowed by this Code, at the design temperature for 
that component; or does not exceed the rated pressure at 
design temperature for that component in the applicable 
standard listed in Table 926.1. 

902.2.4 Ratings at Transitions. Where piping sys- 
tems operating at different design conditions are con- 
nected, a division valve shall be provided, which shall be 
designed for the higher pressure-temperature condition. 

902.3 Allowable Stresses and Other Stress Limits 

902.3.1 Allowable Stress Values 

(a) General The allowable stresses to be used for 
design calculations shall conform to those in Mandatory 
Appendix I, unless modified by other requirements of 
this Code. 

For pipe and tube that do not contain longitudinal or 
spiral joints, Mandatory Appendix I shows the basic 
allowable stress S. 

For pipe and tube that contain longitudinal or spiral 
joints, Mandatory Appendix I shows the product of the 
basic allowable stress S and the longitudinal or spiral 
joint factor £. SE is then the allowable stress. For such 
materials, divide the value shown in the table by the 
joint factor £ to obtain the basic allowable stress S for 
Code computations in which the joint factor need not 
be considered. 

Allowable stresses for materials not listed in Manda- 
tory Appendix I shall be as listed in ASME B3L1 or 
shall be determined using the bases in paras. 902.3.1(b) 
through (f), as applicable. 

(b) For Cast Iron, Basic allowable stress values at tem- 
perature for cast iron (except as covered in para. 904.1.2) 
shall not exceed the lower of the following: 

(1) one-tenth of specified minimum yield strength 
at room temperature 



(2) one-tenth of tensile strength at temperature 1 

(c) For Malleable and Ductile Iron. Basic allowable 
stress values at temperature for malleable and ductile 
iron shall not exceed the lower of the following: 

(1) one-fifth of specified minimum tensile strength 
at room temperature 

(2) one-fifth of tensile strength at temperature 1 

(d) Other Metals. Basic allowable stress values for 
materials other than bolting materials, cast iron, and 
malleable iron shall not exceed the lowest of the fol- 
lowing: 

(1) one-fourth of specified minimum tensile 
strength at room temperature 

(2) one-fourth of tensile strength at temperature 1 

(3) two-thirds of specified minimum yield strength 
at room temperature 

(4) two-thirds of yield strength at temperature 1 

(e) Thermoplastics, The basic allowable stress for pres- 
sure design only of thermoplastic materials shall be one- 
half the hydrostatic design basis at the design tempera- 
ture, as determined from test data obtained in accor- 
dance with ASTM D 1598 or analyzed in accordance 
with ASTM D 2837. 

(f) Reinforced Thermoset Resins, The basic allowable 
stress for pressure design only of reinforced thermoset- 
ting resin materials shall be one-half the hydrostatic 
design basis at the design temperature, as determined 
from test data obtained in accordance with ASTM 
D 1598, or analyzed in accordance with Procedure B of 
ASTM D 2992. Data obtained by the method of ASTM 
D 2143 may be used if analyzed by Procedure A of ASTM 
D 2992. 

(g) Shear and Bearing Stresses. Allowable stress values 
in shear shall be 0.80 times, and allowable stress values 
in bearing shall be 1.60 times, the basic allowable stress 
value S. 

(h) Pipe Support Elements. For allowable stresses see 
para. 921.1.1. 

902.3.2 Limits of Calculated Stresses due to Sus- 
tained Loads and Thermal Expansion or Contraction 

(a) Internal Pressure Stresses. The calculated stress due 
to internal pressure shall not exceed the allowable stress 
values SE given in Mandatory Appendix I except as 
permitted elsewhere in para. 902.3. 

(b) External Pressure Stresses. Stresses due to external 
pressure shall be considered acceptable when the wall 
thickness of the piping component and its means of 
stiffening meet the requirements of paras. 903 and 904. 

(c) Stresses due to Expansion and Contraction. The 
allowable stress range S A for expansion stresses in sys- 
tems stressed primarily in bending and torsion shall 



1 The tensile (or yield) strength at temperature is derived by multi- 
plying the average expected tensile (or yield) strength at tempera- 
ture by the ratio of the specified minimum tensile (or yield) strength 
at room temperature to the average expected tensile (or yield) 
strength at room temperature. 



10 



Copyright © 2008 by the American Society of Mechanical Engineers. 
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ASME B31.9-2008 



be determined in accordance with ASME B31.1, para. 
102.3.2(C), using basic allowable stresses S from 
Mandatory Appendix I of this Code. 

(d) Additive Stresses. The sum of the longitudinal 
stresses due to pressure, weight, and other sustained 
loads shall not exceed the allowable stress in the hot 
condition S/,. Where the sum of these stresses is less than 
S/„ the difference between S h and this sum may be added 
to the term 0.25 S h in eq. (1) of ASME B31.1, para. 
102.3.2(C) for determining the allowable stress range S A . 

(e) Longitudinal Pressure Stress. The longitudinal pres- 
sure stress S LP is determined by dividing the end force 
due to internal pressure by the cross-sectional area of 
the pipe wail 

902.3.3 Limits of Calculated Stresses Due to Occa- 
sional Loads 

(a) Operation. The sum of the longitudinal stresses 
produced by pressure, live and dead loads, and those 
produced by occasional loads, such as wind or earth- 
quake, shall not exceed 1.33 times the allowable stress 
values S in Mandatory Appendix I. It is not necessary 
to consider wind and earthquake as occurring concur- 
rently. 

(b) Test. Stresses due to test conditions are not subject 
to the limitations of para. 902.3. It is not necessary to 
consider other occasional loads, such as wind and earth- 
quake, as occurring concurrently with the live, dead, 
and test loads existing at the time of the test. 

902.4 Allowances 

902.4.1 Corrosion or Erosion. When corrosion or 
erosion is expected, the wall, thickness shall be increased 
over that required by other design requirements, unless 
other means of corrosion control such as coatings or 
cathodic protection are relied on. This allowance shall 
be consistent with the expected life of the piping, as 
judged by the engineer. 

902.4.2 Threading and Grooving. The calculated 
minimum thickness of metallic pipe or tubing that is to 
be threaded shall be increased by an allowance equal to 
thread depth, dimension h in ASME Bl.20.1, or equiva- 
lent. For machined surfaces or grooves if the tolerance 
is not specified, it shall be assumed to be V 64 in. (0.4 mm) 
in addition to the specified depth of cut. 

For plastic pipe, the recommendations for threading 
and derating in the applicable standard listed in 
Table 926.1 shall be followed. 

902.4.3 Joint Efficiency Factors. Longitudinal or spi- 
ral weld joint efficiency factors are required by this Code 
and are included in the allowable stress values SE in 
Mandatory Appendix L Table 902,4.3 states the factor E 
for several types of longitudinal or spiral welds. 

902.4.4 Mechanical Strength. The wall thickness of 
pipe should be increased where necessary for mechani- 
cal strength to prevent damage, collapse, excessive sag 



Table 902.43 Joint Factors, £ 





Weld Joint 




Efficiency 


Type of Longitudinal or Spiral Joint 


Factor, E 


Single butt weld 


0.80 


Double butt weld 


0.90 


Single or double butt weld with 100% 


1.00 


radiography or ultrasonic examina- 




tion [Note (1)] 




Electric resistance weld 


0.85 


Furnace butt weld (or continuous 


0.60 


weld) 




ASTiVi A 211 spiral joint 


0.75 



NOTE: 

(1) Acceptance standards are those in ASME B31.1. 



or buckling of pipe due to superimposed loads from 
supports or other causes; or, if this is impractical or 
would cause excessive local stresses, the superimposed 
loads shall be reduced or eliminated by other design 
methods. 



PART 2 
PRESSURE DESIGN OF PIPING COMPONENTS 

903 CRITERIA FOR PRESSURE DESIGN OF PIPING 
COMPONENTS 

Components manufactured in accordance with the 
specifications and standards listed in Table 926.1 or in 
Mandatory Appendix I shall be considered suitable for 
use at the pressure-temperature ratings or allowable 
stresses in accordance with para. 902.2. Components not 
manufactured in accordance with those specifications 
and standards shall be used only in accordance with 
para. 902.2.2. 

The rules in para. 904 usually are for the pressure 
design of components not covered in para. 902.2, but 
may be used for a more rigorous or special design of 
components covered in para. 902.2. The designs shall 
be checked for adequacy of mechanical strength under 
applicable loadings stated in para. 901. 



904 PRESSURE DESIGN OF COMPONENTS 
904.1 Straight Pipe 

904.1.1 Straight Pipe Under Internal Pressure 

(a) Steel, Alloy, and Nonferrons Pipe. The minimum 
wall thickness of pipe wall, including allowances, shall 
not be less than that determined by eq. (1). 



*-m 



PD 

2SE 



+ A 



(1) 



11 



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ASME B31.9-2008 



Design pressure shall not exceed that determined by 
eq. (2). 



Table 904.2.1 Pipe Thickness for Bends 



(08) 



p 



2SE (t m - A) 
D 



(2) 



The engineer may, at his option, use the values of t m 
and P determined by the applicable equations in ASME 
B31.1. 

(1) If pipe is ordered by its nominal wall thickness, 
the manufacturing tolerances on wall thickness must be 
taken into account. After the minimum wall thickness 
t m is determined, this minimum thickness shall be 
increased to provide the manufacturing tolerance 
allowed in the applicable pipe specification. The next 
heavier commercial wall thickness shall then be selected. 

(2) When computing the design pressure for a pipe 
of a definite minimum wall thickness t nlr the value of 
pressure obtained by eq. (2) may be rounded to the next 
higher increment of 10 psi (69 kPa). 

(b) Ductile Iron Pipe, The thickness of ductile iron pipe 
shall be determined from one of the following: 

(1) ANSI/AWWA C150/A21.50 or C151/A21.51 

(2) ANSI A21.14 or A21.52 

(3) Federal Specification WW-P-421 

The tabulated thicknesses in these standards include 
allowances for foundry tolerances and water hammer. 

(c) Straight Nonmetallic Pipe. The maximum pressure 
ratings for plastic and other nonmetallic pipe shall be 
as given in the applicable standards listed in Table 926.1. 

904.1.2 Straight Metallic Pipe Under External Pres- 
sure. In determining wall thickness and stiffening 
requirements for straight pipe under external pressure, 
the procedures outlined in UG-28 of Section VIII, Divi- 
sion 1 of the ASME BPV Code shall be followed. 

904.2 Curved and Mitered Segments of Pipe 

904.2.1 Pipe Bends 

(a) Thickness of Bends. The minimum wall thickness 
t m at any point in a completed pipe bend shall not be 
less than that required by para. 904.1.1. Table 904.2.1 
may be used as a guide in specifying wall thickness for 
ordering pipe to be bent. 

(b) Flattening of Bends. Flattening of a bend, as mea- 
sured by the difference of maximum and minimum 
diameters, shall not exceed 8% of the average measured 
outside diameter of the pipe before bending. 

Greater flattening may be permitted or less flattening 
may be required if specified by the engineering design. 

904.2.2 Miter Joints. Thickness determined in 
accordance with para. 904.1.1 does not allow for discon- 
tinuity stresses at the joint between mitered segments 
of pipe. These discontinuity stresses are negligible for 
miter angles of 3 deg or less in any service, and may be 
neglected for miters in nonflammable, nontoxic liquid 
service at pressures of 50 psig (345 kPa) or less, and 



Radius of 
Bends, Pipe 
Diameters, D n 

[Note (1)3 



Minimum Thickness 

Recommended Prior to 

Bending, t m 



6 or greater 
5 

4 

3 



1.06 
1.08 
1.14 
1.24 



NOTE: 

(1) Interpolation is permissible for a radius other than those 
listed. 



Fig. 904.2.2 Nomenclature for Miter Joints 




for unvalved vents to atmosphere. See Fig. 904.2.2 for 
nomenclature. 

(a) Allowable Pressure. For other services and for pres- 
sures in excess of 50 psig (345 kPa), the maximum allow- 
able pressure for miter joints where 6 does not exceed 
22V 2 deg shall be the lower positive value calculated by 
eqs. (3 A) and (3B). 



SET) 



H \T + 0.64 tan 



'W 



P = 



SETi R 



r 2 



r 2 \R^ - 0.5r 2 



(3A) 



(3B) 



Equations (3A) and (3B) apply only w 7 hen R 2 is at least 
as great as the value calculated by eq. (4). 



12 



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ASME B31.9-2008 



(U.S. Customary Units) 



(SI Units) 



R, - 



R, = 



1 D 
tan + 2 



25.4 D 
tan + 2 



(4) 



(b) Other Miters. Miter joints not covered above shall 
meet the requirements of para. 904.7. 

9043 Branch Connections 

9043.1 General In para. 904.3, requirements are 
presented tor design of branch connections in which the 
angle between the axes of the branch and main is 45 deg 
to 90 deg, inclusive, and the axes intersect. Branch con- 
nections may be made by any of the following methods: 

(a) Fittings. Tees, extruded outlets, laterals, crosses, 
etc., manufactured in accordance with a standard listed 
in Table 926.1. 

(b) Outlet Fittings. Cast or forged, integrally rein- 
forced, welding outlet fittings, nozzles, forged cou- 
plings, and similar items, attached to the main by 
welding. 

(c) Direct Connection to the Main. Welding the branch 
pipe directly to the main, with or without added rein- 
forcement, as shown in details of branch connections in 
Figs. 927.4.6-1 and 927.4.6-2 and the rules of para. 904.3.2. 

id) Mechanically Formed Tee Connections in Copper Tube. 
See para. 930.2. 

9043.2 Strength of Branch Connections 

(a) General A main having a branch connection is 
weakened by the branch opening. Unless the wall thick- 
ness of the main and branch are sufficiently in excess 
of that required to sustain the pressure, it is necessary 
to provide added reinforcement. 

(b) Multiple Openings. In the case of multiple open- 
ings in the main, the rules of this paragraph are applica- 
ble only if the distance between their centers is at least 
the sum of their inside diameters, d. Otherwise, the 
requirements in para. 104.3.1(G.7) of ASME B3 1.1 must 
be met. 

(c) Branch Connections Not Requiring Added Reinforce- 
ment, It may be assumed without calculation that a 
branch connection has adequate strength to sustain the 
internal and external pressure that will be applied to it if 

(1) the branch connection utilizes a fitting (tee, lat- 
eral, or cross) in accordance with para. 903. 

(2) the branch connection is made by welding a 
threaded or socket- welding coupling or half coupling 
directly to the main, when the branch size does not 
exceed NPS 2 (DN 50) or one-fourth the nominal diame- 
ter of the main. The minimum wall thickness of the 
coupling shall be not less than that of the unthreaded 
branch pipe. See Fig. 927.4.6-2 for permissible welds. 



(3) the branch connection is made by welding an 
integrally reinforced outlet fitting (having a threaded, 
socket, or butt-welding outlet) to the main, provided 
the fitting is made from materials listed in Mandatory 
Appendix I, and provided it has been demonstrated by 
full-scale internal pressure tests or other means 
described in para. 904,7 that the branch fitting and its 
joint are at least as strong as the main or branch pipes. 

(4) the branch connection design pressure is less 
than the pressure, P obtained from eq. (5), when solved 
for the configuration of the joint, no reinforcement is 
required. The equation gives the maximum pressure 
allowed without reinforcement by equating the removed 
required area in the main to the inherent excess areas 
in the main and branch. If the design pressure is higher 
than P, see para. 904.3.3. 



SE m SE b [T m (D b - 2T b ) + ?1(5 + sin a)] 
SE b D m (D b -2T b ) + 5S m T b D b 



(5) 



where 

D„ 

D m 

P 

SE b 

SF 



T b - 



T n7 = 



the O.D. of the branch, in. (mm) 
the O.D. of the main, in, (mm) 
the maximum pressure of the joint without 
reinforcement, psi (kPa) 
the allowable stress for the branch material, 
psi (kPa) 

the allowable stress of the main material, psi 
(kPa) (For welded, pipe, E = 1.0 if the weld in 
the main does not intersect the branch joint.) 
the thickness of the branch less the manufac- 
turing tolerance and less the corrosion allow- 
ance, if any, in. (mm) 

the thickness of the main net of manufactur- 
ing tolerance and a corrosion allowance, in. 
(mm) 

the angle between the axis of the main and 
the axis of the branch 



90433 Reinforcement of Branch Connections. If 

added reinforcement is required for a branch connection 
as determined by para. 904.3.2(c)(4) the criteria for such 
reinforcement along with rules for proportioning and 
attaching such reinforcement are given in para. 
104.3.1(D) of ASMEB31.1. 

9043.4 Extruded Outlet Headers. If integrally rein- 
forced extruded outlet headers are used, they shall be 
reinforced as required by para. 104.3.1(G) of ASME 
B31.1. 

904.4 Closures 

904.4.1 General. Closures shall be made by use of 
closure fittings, such as plugs, caps, or blind flanges in 
accordance with para. 903, or by use of flat plate closures 
such as those shown in Fig. 927.4.5-1. Flat plate closures 
shall not be secured with a single fillet weld. 



13 



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ASME B31.9-2008 



The minimum required thickness, t c for flat plate clo- 
sures is calculated by eq. (6). 

t c = dJCtVS + A (6) 

where 

C = 05t m /T, but not less than 0.3 

S = allowable stress of closure material 

904.4.2 Openings in Closures. Openings in closures 
may be made by welding, extruding, or threading. 
Attachment to the closure shall be in accordance with 
the requirements for the corresponding type of branch 
connection in para. 904.3.3, including the need and pro- 
vision for added reinforcement. If the size of the opening 
is greater than half the inside diameter of the closure, 
the opening shall be designed as a reducer in accordance 
with para. 904.6. 

904.5 Pressure Design of Flanges and Blanks 

904.5.1 General. Flanges manufactured in accor- 
dance with a standard listed in Table 926.1 are suitable 
for use in accordance with para. 903. Other flanges shall 
be designed in accordance with Appendix II, Section 
VIII, Division 1 of the ASME BPV Code. 

904.5.2 Blind Flanges. Blind flanges manufactured 
in accordance with a standard listed in Table 926.1 are 
suitable for use in accordance with para. 903. Other blind 
flanges shall be designed in accordance with UG-34 of 
Section VIII, Division 1 of the ASME BPV Code. 

904.5.3 Blanks. The minimum required thickness 
of a. permanent blank installed between two flanges shall 
be calculated by eq. (7). 



t r 



d g .^3PA6S + A 



(7) 



where 

S = allowable stress of blank material. Use S F if 
material is a casting. 

Blanks used only for testing with an incompressible 
fluid shall be calculated in accordance with eq. (7), 
except that P shall be the test pressure and S may be 
taken as 0.95 times the specified minimum yield strength 
of the blank material. 

904.6 Reducers 

904.6.1 General. Reducers manufactured in accor- 
dance with a standard listed in Table 926.1 are suitable 
for use with pipe of the same nominal thickness. 

904.6.2 Segmented Reducers. The minimum wall, 
thickness of segmented (orange peel) reducers fabricated 
with longitudinal welds shall be determined in accor- 
dance with para. 904.1.2, using a weld joint efficiency 
factor of 0.6. The slope of the reducing section shall not 
be at an angle greater than 30 deg to the axis of the pipe. 



904.7 Pressure Design of Other Pressure Containing 
Components 

904.7.1 Listed Components. Other pressure con- 
taining components manufactured in accordance with 
a standard listed in Table 926.1 are suitable for use in 
accordance with para. 903. 

904.7.2 Unlisted Components, Pressure containing 
components made of listed materials but not made in 
accordance with a specification or standard listed in 
Table 926.1 or Mandatory Appendix I shall be substanti- 
ated by at least one of the following: 

(a) engineering calculations 

(b) experimental stress analysis such as described in 
Appendix 6 in Section VIII, Division 2 of the ASME 
BPV Code 

(c) proof test in accordance with UG-101 in Section 
VIII, Division 1 of the ASME BPV Code 

If differences in size and proportion are small, compo- 
nents may be designed by interpolation between similar 
configurations that have been proven by one of the pro- 
cedures described above, or that conform to a listed 
standard. 



PART 3 
SELECTION AND LIMITATION OF COMPONENTS 

905 PIPE 

905.1 General 

905.1.1 Listed Pipe. Pipe manufactured in accor- 
dance with a specification or standard listed in Table 

926.1 or Mandatory Appendix I, as qualified by the 
Notes, may be used in accordance with its ratings or 
allowable stresses, within other limitations in para. 905, 
and within the limitations on joints in Chapter II, Part 
4 and on materials in Chapter III. 

905.2 Specific Limitations 

905.2.1 Cast Iron Pipe. Cast iron pipe shall not be 
used above ground in oil or other flammable liquid 
service, nor in compressed gas service. 

905.2.2 Steel Pipe. Furnace butt weld steel pipe 
shall not be used for flammable or combustible liquids. 

905.2.3 Copper Alloy Pipe and Tube. Copper pipe 
and tube shall not be used for flammable or combustible 
liquids except as permitted in para. 922.3.1(c). 

905.2.4 Nonmetallic Pipe. Unlisted reinforced ther- 
mosetting resin pipe shall not be used. 



905.2.5 Thermoplastics Pipe. 

limitations on thermoplastics. 



See para. 923.3.2 for 



14 



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ASME B31.9-2008 



906 FITTINGS, BENDS, AND INTERSECTIONS 



906.1 Fittings 



Fittings manufactured in 



906.1.1 Listed Fittings 

accordance with a specification or standard listed in 
Table 926.1 or Mandatory Appendix I may be used in 
accordance with their ratings or allowable stresses, 
within other limitations in para. 906, and within the 
limitations on joints in Chapter II, Part 4 and on materi- 
als in Chapter III. 

906.2 Bends and Mster Joints 

See para. 904.2.2(a) for service limitations on restricted 
miter joints. 

906.3 Limitations on Fittings 

Cast iron fittings shall not be used in flammable liquid 
or gas service. See para. 923.3.2 for limitations on ther- 
moplastics. 

907 VALVES 

907.1 General 

907.1.1 Listed Valves. Valves manufactured in 
accordance with a standard listed in Table 926.1 may 
be used in accordance with their ratings, within other 
limitations in para. 907, and within the limitations on 
joints in Chapter II, Part 4 and on materials in Chap- 
ter III. 

907.1.2 Unlisted Valves. Valves not manufactured 
in accordance with a listed standard shall be used only 
within the manufacturer's recommendations as to ser- 
vice and ratings, and within the limitations on compara- 
ble listed valves, considering composition, mechanical 
properties, dimensions, method of manufacture, and 
quality control. Otherwise, the valves shall be qualified 
in accordance with para. 904.7.2. 

907.2 Marking 

Each valve shall bear markings in accordance with 
MSS SP-25, including the manufacturer's name or trade- 
mark, the material of construction, and symbols to indi- 
cate the service conditions for which the manufacturer 
rates the valve. Other markings shall, be included if 
required by the applicable standard. 

908 FLANGES, BLANKS, GASKETS, AND BOLTING 

908.1 General 

908.1.1 Listed Components. Flanges, blanks, gas- 
kets, and bolting manufactured in accordance with a 
standard listed in. Table 926.1 may be used in accordance 
with their ratings, within manufacturers' recommenda- 
tions, within other limitations in para. 908, and within 



the limitations on joints in Chapter II, Part 4 and on 
materials in Chapter III. 

908.2 Flange Facings 

Flange facings shall be in accordance with the stan- 
dards listed in Table 926.1, or as provided in MSS SP-6. 
When bolting raised-face steel flanges to flat-face cast 
iron flanges, bolting torque should be limited to prevent 
cracking the cast iron flange; otherwise, steel flanges 
should be furnished with a flat-face, and full-face gaskets 
shall be used. 

908.3 Gaskets 

Material, thickness, and type of gasket shall be selected 
to suit the fluid to be handled and the design pressure 
and temperature. 

908.4 Bolting 

Bolts, nuts, and washers shall conform to applicable 
standards listed in Table 926.1. 



PART 4 
SELECTION AND LIMITATION OF 

JOINTS 

910 PIPING JOINTS 

The type of joint used shall be suitable for the design 
conditions and the fluid handled, and shall be selected 
with consideration of joint tightness and mechanical 
strength. 



911 WELDED JOINTS 

911.1 Metallic Pipe 

Welded joints shall only be used for materials for 
which welding procedures, welders, and welding 
machine operators have been qualified as required in 
Chapter V. 

911.1.1 Butt and Miter Welds. Butt and miter joint 
welds shall be made in accordance with para. 927.4.2, 
and shall be full penetration welds. (Backing rings are 
not recommended.) 

911.1.2 Socket Welding. Socket welds shall be 
made in accordance with para. 911.1.3. In addition, 
dimensions of socket- type joints shall conform to those 
in standards listed in Table 926.1, 

911.1.3 Fillet Welds. Fillet welds in properly 
designed connections shall be made in accordance with 
para. 927.4.3. 

911.1.4 Seal Welds, Seal welds are intended only 
to provide leak tightness for threaded joints and are not 
considered to add strength to the joint. 



15 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



ASME B31.9-2008 



911.2 Nonmetallic Pipe 

911.2.1 Thermoplastic Welding. Welds in thermo- 
plastic materials shall conform to the requirements in 
para. 934.1.3. 

911.2.2 Thermoplastic Socket Welding. Dimensions 
of socket-type joints shall conform to those in standards 
for fittings listed in Table 926.1. 

912 FLANGED JOINTS 

Flanged joints shall meet the requirements in para. 908. 

913 MECHANICAL AND PROPRIETARY JOINTS 

Grooved, extruded, expanded, rolled, O-ring, clamp, 
gland-type, and other mechanical or proprietary joints 
may be used where experience or tests in accordance 
with para. 904.7 have demonstrated that the joint is 
safe for the operating conditions and the fluids being 
transported, and where adequate provision is made to 
prevent separation of the joint. All such joints shall be 
used within the manufacturer's limitations on 
pressure-temperature ratings and other recommenda- 
tions for installation and use. 

913.1 Limitations on Mechanical and Proprietary 
Joints 

Joints dependent on friction characteristics or resil- 
iency of combustible or low melting point materials for 
mechanical continuity or leak tightness shall not be used 
for flammable fluids or gases inside buildings. 

914 THREADED JOINTS 

Threaded joints may be used within the limitations 
on fittings in para. 906, limitations on materials in Chap- 
ter III, and other limitations herein. 

914.1 Acceptable Types 

Threads on pipe and fittings shall be tapered pipe 
threads in accordance with ASME Bl.20.1 or other appli- 
cable standards listed in Table 926.1, except that threads 
in wrought steel couplings NFS 2 (DN 50) and smaller 
may be straight pipe threads. Threads other than tapered 
pipe threads may be used where tightness of the joint 
depends on a seal weld or seating surface other than the 
threads, and where experience or test has demonstrated 
that such threads are suitable. 

914.2 Limitations on Threaded Joints 

(a) Threaded joints shall not be used where severe 
erosion, crevice corrosion, shock, or vibration are 
expected to occur. 

(b) Metallic pipe with a wall thickness less than that 
of standard wall in ASME B36.10M shall not be threaded, 
regardless of service. 



(c) Plastic pipe with wall thickness less than that of 
Schedule 80 shall not be threaded. 

id) Polyethylene pipe and polybutylene pipe shall not 
be threaded. 

915 FLARED, FLARELESS, AND COMPRESSION 
JOINTS 

Flared, flareless, and compression type tubing fittings 
and joints may be used within the limitations of applica- 
ble standards listed in Table 926,1, on materials in Chap- 
ter 111, and other limitations herein. 

Fittings and joints shall be compatible with the tubing 
with which they are used, and shall be used within the 
manufacturer's pressure-temperature ratings. Vibration 
and thermal cycling shall be considered in each appli- 
cation. 

916 BELL AND SPIGOT JOINTS 

916.1 Caulked or Leaded Joints 

Bell and spigot joints, caulked with lead and packing 
material, may be used only for water service up to 100°F 
(38°C), where adequate provision is made to prevent 
separation of the joints. See ANSFAWWA C600 for joints 
in cast iron pressure piping. 

916.2 Push-Type Elastomer Gasket 

Push-type joints with elastomer gaskets may be used 
where experience or tests have demonstrated that the 
joint is safe for the operating conditions and the fluid 
being transported, and where adequate provision is 
made to prevent separation of the joints. 

917 BRAZED AND SOLDERED JOINTS 
917.1 General 

Brazed and soldered socket-type joints shall be made 
in accordance with para. 928 and with brazing or solder- 
ing filler metals that are compatible with the base mate- 
rial and with the pressure, temperature, and other 
service conditions. 

917*2 Brazed Joints 

Socket-type brazed joints may be used within the limi- 
tations on materials in Chapter III. 

9173 Soldered Joints 

917.3.1 General. Soldered socket- type joints may 
be used within the pressure™ temperature limitations in 
Table 917.3. Soldered joints other than socket-type shall 
not be used. 

917.3.2 Limitations. Soldered joints shall not be 
used for flammable or toxic gases or liquids. They shall 
not be used for compressed air or other gases in tubing 



16 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



ASME B31.9-2008 



Table 917.3 Rated Internal Working Pressures of Joints Made With Copper Water Tube and Solder Joint 

Fittings, psig 





Maximum 

Service 

Temperature, 




Types K, 


L, N\ Copper Water Tube in 


Nominal Sizes, in. 




Solder or Brazing 




Liquids and Gases [Note (l)] 




Saturated Steam 


Alloy 








5-8 


10-12 


and Condensate, 


Used in joints 


op 


%~1 


lVl-2 


2Y2-4 


[Note (2)] 


[Note (2)] 


All Sizes 


50-50 Tin-Lead ASTM 


100 


200 


175 


150 


135 


100 




B 32 Gr 50A 


150 


150 


125 


100 


90 


70 






200 [Note (2)] 


100 


90 


75 


70 


50 






250 [Note (2)] 


85 


75 


50 


45 


40 


15 


95-5 Tin-Antimony 


100 


500 


400 


300 


270 


150 




ASTM B 32 Gr95TA 


150 


400 


350 


275 


250 


150 






200 [Note (2)] 


300 


250 


200 


180 


140 






250 [Note (2)] 


200 


175 


150 


135 


110 


15 


Brazing Alloys 


200 [Note (2)] 


[Note (3)] 


[Note (3)] 


[Note (3)] 


[Note (3)3 


[Note (3)] 






250 [Note (2)] 


300 


210 


170 


150 


150 


15 




350 [Note (2)] 


270 


190 


150 


150 


150 


120 



NOTES: 

(1) See limitations in para. 917.3.2. 

(2) See paras. 900.1.2(d) and (e) for pressure and temperature limits under this Code. 

(3) Rated pressure for temperatures up to 200°F is that of the tube being joined. 



over 4.125 in. (105 mm) O.D. unless the maximum pres- 
sure is limited to 20 psig (138 kPa). 

PARTS 
EXPANSION, FLEXIBILITY, AND SUPPORT 

919 EXPANSION AND FLEXIBILITY 

919.1 General 

In addition to design requirements for pressure, 
weight, and other loadings, piping systems subject to 
thermal expansion or contraction, or to similar move- 
ments imposed by other sources shall be designed to 
prevent: 

(a) failure of piping or supports from overstress or 
fatigue 

(b) leakage of joints 

(c) detrimental stresses or distortion in connected 
equipment (pumps, turbines, valves, etc.) resulting from 
excessive thrusts and moments 

919.2 Concepts 

919.2.1 General The treatment of flexibility analy- 
sis in this Code covers only the simplest applications. 
For piping systems not compatible with this simplified 
approach, the user is directed to Chapter II, Part 5 of 
ASME B31.1. The concepts, methods, and requirements 
therein are acceptable under this Code. 

919*2.2 Means of Providing Flexibility. Flexibility 
may be increased by one or more of the following means: 
(a) adding elbows, bends, or loops where feasible 



(b) installing expansion joints, properly guided and 
restrained 

(c) installing rotary joints, properly guided and 
restrained 

919.23 Flexibility in Nonmetallic Piping. Particular 
care must be taken in selecting the methods given in 
para. 919.2.2 when laying out nonmetallic piping sys- 
tems, because they are difficult or impossible to analyze, 
have very limited capacity for overstress, are subject to 
brittle failure, and may have high coefficients of thermal 
expansion and nonlinear stress-strain characteristics. 

9193 Properties for Analysis 

9193.1 Coefficients of Thermal Expansion. Table 
919.3.1 contains data on thermal expansion characteris- 
tics of many of the metallic and nonmetallic materials 
used in this Code. 

919.4 Analysis, Metallic Piping 

919.4.1 Requirements for Analysis 

(a) Simplified Analysis. No formal analysis is required 
for systems that meet one of the following criteria: 

(1) The system duplicates a successfully operating 
installation or replaces a system with a satisfactory ser- 
vice record. 

(2) The system is of ductile material (e.g., there are 
no cast iron fittings); the segment being analyzed has no 
more than two anchors and no intermediate restraints; it 
has no more than two pipe sizes, differing by one stan- 
dard size; the least nominal wall thickness is no less 



(08) 



17 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



ASME B31.9-2008 



Material 



Table 919.3.1 Moduli of Elasticity and Thermal Expansion Coefficients 



Modulus of 
Elasticity, 
psi x 10" 6 



Coefficient of 
Thermal Expansion, 


Linear Thermal Expansion, in./lOO ft, 
Between 70°F and indicated Temperature, 


°F 


in. /in., °F x 10~ 6 
[Note (1)] 





25 


50 


70 


100 


125 


633 


-0.49 


-0.32 


-0.14 





0.23 


0.42 


9.27 


-0.72 


-0.46 


-0.21 





0.34 


0.62 


12.69 


-0.97 


-0.63 


-0.28 





0.46 


0.85 


5.76 


-0.49 


-0.32 


-0.14 





0.21 


0.38 


5.97 


-0.46 


-0.30 


-0.14 





0.21 


0.39 


9.50 


-0.80 


-0.51 


-0.23 





0.34 


0.63 



Carbon steel 

Austenitic stainless steel 

Aluminum 

Gray cast iron 

Ductile iron 

Copper C12200 
(99.9Cu) 

Copper CA 23000 
(red brass) (85Cu) 

ABS 1210 
1316 
2112 

CPVC 4120 

PVC 1120 
1220 
2110 
2120 

PB 2110 

PE 2306 
3306 
3406 

PP 1110 
1208 
2105 

RTRP 



27.5 
29.0 
10.0 
13.0 

17.0 
17.0 



0.25 
0.34 



0.42 

0.42 
0.41 
0.34 



0.09 
0.13 
0.15 



10.40 



55.0 
40.0 
40.0 

35.0 

30.0 
35.0 
50.0 
30.0 

72.0 

80.0 
70.0 
60.0 

48.0 
43.0 
40.0 



-0.87 



-0.56 



-0.25 



-0.84 



-1.73 



0.37 



1.32 





1.98 


0.96 





1.44 


0.96 





1.44 



1.26 



0.72 





1.08 


0.84 





1.26 


1.20 





1.80 


0.72 





1.08 



2.59 



1.92 





2.88 


1.68 





2.52 


1.44 





2.16 


1.15 





1.73 


1.03 





1.55 


0.96 





1.44 



0.69 



2.31 



4.75 



Consult manufacturer 



NOTE: 

(1) Average of the mean values over the temperature range for which data are shown. 



than 75% of the greatest; and thermal expansion in the 
segment satisfies eq. (8): 



(U.S. Customary Units) 



(SJ Units) 



DY/(L - U) 2 < 0.03 



DY/(L - Uf < 208.3 



(8) 



where 

D = the nominal size of the larger pipe in the 

segment 
L = developed length of line axis, ft (m) 



U — anchor distance (length of straight line joining) 
Y — resultant of movements to be absorbed by pipe 
lines, in. (mm) 

NOTE: There is no assurance that eq. (8) is always accurate or 
conservative, especially for nearly straight sawtooth segments or 
for unequal leg U-bends where IAJ is more than 2.5. There is no 
assurance that end reactions will be acceptably low. 

(3) The system is laid out with a conservative mar- 
gin of inherent flexibility, or employs joining methods, 
expansion devices, or a combination of joining method 
and expansion devices in accordance with applicable 
manufacturers' instructions. 



18 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



ASME B31.9-2008 



150 



175 



Table 919.3.1 Moduli of Elasticity and Thermal Expansion Coefficients 

Linear Thermal Expansion, In./lOO ft, 
Between 70°F and Indicated Temperature, °F 



200 



225 



250 



275 



300 



325 



350 



375 



Material 



0.61 
0.90 
1.23 
0.55 
0.57 
0.91 

1.00 



3.36 



6.91 



0.80 
1.18 
1.62 
0.73 
0.76 
1.20 

1.31 



4.41 



9.07 



0.99 
1.46 
2.00 
0.90 
0.94 
1.48 

1.62 



1.21 
1.75 
2.41 
1.00 
1.13 
1.77 

1.93 



1.40 
2.03 
2.83 
1.27 
1.33 
2.05 

2.25 



1.61 
2.32 
3.24 

1.45 
1.53 
2.34 

2.56 



1.82 
2.61 
3.67 
1.64 
1.72 
2.62 

2.87 



2.04 
2.90 
4.09 
1.83 
1.93 
2.91 

3.18 



2.26 
3.20 
4.52 
2.03 
2.13 
3.19 

3.49 



2.48 
3.50 
4.95 
2.22 
2.36 



Carbon steel 

Austenitlc stainless steel 

Aluminum 

Gray cast iron 

Ductile Iron 

Copper C12200 
(99.9Cu) 

Copper CA 23000 
(red brass) (85Cu) 

ABS 1210 
1316 
2112 

CPVC 4120 

PVC 1120 
1220 
2110 
2120 

PB 2110 

PE 2306 
3306 
3406 

PP 1110 
1208 
2105 



RTRP 



(b) Other Methods of Analysis. Piping systems which 
do not meet the criteria of 919.4.1(a) shall be analyzed 
by suitable approximate or conservative methods as out- 
lined in ASME B31.1, paras. 119.7.1(C) and (D), and as 
directed elsewhere in para. 119 of ASME B31.1. 

919.5 Movements 

Movements caused by thermal expansion or contrac- 
tion and other similar loadings shall be determined for 
consideration of obstructions and design of supports. 

919.6 Cold Spring 

Cold spring is the intentional displacement of piping 
during assembly. When applied, it is normally to com- 
pensate for one-half of the total expected pipe movement 
due to expansion. Possible benefits of cold spring include 



(a) reduced likelihood of overstrain during initial 
operation 

(b) reduced deviation from as-installed hanger posi- 
tions 

(c) reduction of maximum end reactions 

No credit for cold spring is permitted in stress range 
calculations. 



919.7 Reactions 

Terminal reactions and resulting moments shall be 
taken into consideration where supporting structure or 
connected equipment is likely to be affected by such 
loadings. Determination of these loads may require anal- 
ysis as specified in para. 919.4.1(b). 



19 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



ASME B31.9-2008 



920 LOADS ON PIPE-SUPPORTING ELEMENTS 

920.1 General 

Supports, as used in this Code, include rigid hangers 
(that support the line from above without springs), 
spring hangers, supports that bear the load from below, 
and guides and anchors that limit pipe movement as 
well as support loads. 

920.1.1 Loads on Supports. The loads to be consid- 
ered In design of supports are 

(a) dead weight of pipe, fittings, valves, insulation, 
inline equipment, hanger system, and other pipelines 
(if supported from the line under consideration) 

(b) live weight of contents 

(c) weight of test fluid (see para. 920.2) 

(d) occasional loads, such as ice, wind, and earth- 
quake 

Weight of test fluid and occasional loads need not be 
consi dered concurrently. 

920.1.2 Loads on Restraints 

(a) General In addition to the loads described in para. 
920.1.1, anchors, guides, and other restraints shall be 
designed to bear loads resulting from thermal expansion 
and contraction and from other movements of the pip- 
ing, such as those caused by internal pressure. 

(b) Expansion joint Loads. Use of expansion joints usu- 
ally increases reactions at anchors. For corrugated and 
slip joints, in the absence of manufacturer's data, anchor 
reaction may be calculated as the sum of 

(1) operating pressure times area corresponding to 
the maximum inside diameter of the joint corrugations 

(2 ) the force required to cause full rated deflection 
of the joint 

(3) frictional forces at guides and supports 

If the expansion joint is at an elbow or bend, the vector 
forces due to fluid change in. direction must also be 
included. 

920.1.3 Other Loads. Loads from other design con- 
ditions described in para. 901 shall be considered in 
design of both supports and restraints. Loads due to 
shock and vibration should preferably be minimized 
by the use of suitable dampeners or properly placed 
supports and restraints. 

920.2 Test Loads 

920.2.1 Test Loads on Rigid Supports. Rigid sup- 
ports shall be capable of bearing the total load under 
test conditions as well as those of normal operation, 
unless additional supports are provided during testing. 

920.2.2 Test Loads on Spring Hangers. Load condi- 
tions for calculated operation of spring hangers should 
not take test loads into account. The hanger assembly, 
however, shall be capable of supporting the test load 
unless additional supports are provided during testing. 



921 DESIGN OF PIPE-SUPPORTING ELEMENTS 
921.1 General 

Pipe-supporting elements shall be designed to carry 
the sum of all concurrently acting loads described, in 
para. 920. Unless designed to anchor or restrain line 
movements by withstanding the resultant forces and 
moments, they shall permit free movement of the piping 
resulting from thermal expansion or other causes. 

In addition, supports shall be so located and spaced 
as to protect the supported piping from excessive stress 
and distortion. 

921.1.1 Materials and Stresses. Except as permit- 
ted herein, materials for pipe-supporting elements shall 
be listed in Mandatory Appendix I. Allowable stresses 
for pipe-supporting elements shall be one-fifth of the 
minimum tensile strength shown in Mandatory Appen- 
dix I. For carbon steel of unknown specification, the 
allowable stress shall not exceed 9,500 psi (65.5 MPa). 

(a) Threaded Parts. The maximum safe loads shall be 
calculated on the root area of the threads of threaded 
parts. 

(b) Allowable Overstress, An increase in allowable 
stress is permitted up to 80% of specified minimum 
yield strength during hydrostatic testing, not to exceed 
24,000 psi (165.5 MPa) for carbon steel of unknown speci- 
fication. 

(c) Selection of Material Hanger and support materi- 
als shall be compatible with the characteristics of the 
piping materials, so that neither shall adversely affect 
the other. 

921.1.2 Hanger Adjustments. Hangers supporting 
piping NPS 2% (DN 65) and larger shall be designed to 
permit adjustment after erection while supporting the 
load. Threaded parts for adjustment shall be in accor- 
dance with ASME Bl.l. 

Turnbuckles and adjusting nuts shall have full thread 
engagement. Threaded adjustments shall be provided 
with suitable locking devices. 

921.1.3 Support Spacing 

(a) Piping Stresses. Stresses in the piping due to sup- 
port spacing shall not exceed the basic allowable stress 
S when computed on the basis of a support span twice 
as great as the actual span. 

(b) Allowable Deflection. The allowable deflection of 
the pipe between supports shall not exceed the smaller 
of 0.25 in. (6.4 mm) or 15% of the outside diameter of 
the pipe, based on the weight of the pipe, service fluid 
(S.G. < 1.0), and insulation. 

(c) Spacing, Steel Pipe. Figure 921.1.3-1 shows the 
maximum recommended support spacing for standard 
w 7 eight Grade A, Grade B, and Schedule 10 pipe. 

(d) Spacing, Other Materials. The maximum recom- 
mended support spacing for copper and plastic pipe is 
shown in Fig. 921.1.3-2. 



20 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



(08) 



Fig. 921.1.3-1 Support Spans for Standard Wall Steel Pipe 



% 


o 




M O 


O "d 


0* ^ 


s a. 


l-f 


B © 


aa S> 


v: o 


ST <» 


B $ 


&K 


a o 


a> 


S § 


en a. 


18 


2 oo 


2. O 


& 2. 


!.« 


£ o 


o •-+> 


& g 


<« CD 


S o 


3. ^ 


=± 82 


^ e 


p g- 


g w 


55 3 


g 0Q 




CO 


s 


^x 


fiesSj 


»C£T 



55 

50 

45 

40 

35 
c 
co 30 




























































A 


^9 


as, 


ste 


am 

\ 


to 


150 


ps 


9 




































\ 


\ 


\ 










































\ 


V, 




















V 


Vate 


ar,l 


qu 


dS 
\ 


G : 


£ 1. 





/ 




































\ 


\ 




/ 











































V, 












25 


25 
20 
15 
10 








































/ 


35( 


3ps 


ig 






















^ 






In 


terr 


lai 


ore 


/ 

5SU 


re 





























































































0.5 



60 



55 



50 



45 



40 



35 



50 psig ^ 
c 



- 150 psig oo 30 



25 



20 



15 



10 







































































































A 


ir, gas 


steam to 15C 

\ 


psig 

\ 








































\ 


V, 


















Water, 


iqu 


idSG 


s 1.0 






































\ 


\ 


\ 


/ 














































\ 








350 


psig 






































/ 


































Internal 


pressu 


re 





























































































12 



16 



2 3 5 J 

Pipe Size, NPS 

(a) Basic Allowable Stress = 12,000 psi 

Grade A 

[Notes (1) and (2)] 

NOTES: 

(1) For Grade A pipe threaded to NPS 2 and welded above NPS 2. 

(2) Use for grooved pipe. 

(3) For Grade B pipe threaded to NPS 2 and welded above NPS 2. 

(4) Use 12,000 psi chart for grooved joints. 



20 24 30 



0.5 



50 psig 
150 psig 
250 psig 



12 



2 3 5 8 

Pipe Size, NPS 

(b) Basic Allowable Stress = 15,000 psi 

Grade B 

[Notes (3) and (4)3 



16 



20 24 30 



(08) 



Fig. 921.13-2 Support Spans for Copper and Thermoplastic Pipe 



ST 



£* 2. 



30 



25 



20 



m 15 

a 

to 



10 































/ 


/ 










/ 


\ir o 


rga 


s, to 


150 


psic 


,20 


D°F^ 






/ 


f 


























































"\" 






























W 


ater 


\ 
of lie 


\ 

3uid 


,to. 


200 


?sig 


,25 


3°F 






j? 

































14 



12 



10 



Q. 

in 





























/ 














PVC, CPVC: Sch. 80^ 
Sch. 40^ 




















ABS; Sch. 80 
Sch. 40 






























































"PPSch. 


80 









































3/8 1/2 3/4 1 



2 3 4 5 

Nominal Tube Size 

(a) Drawn Temper-ASTIVI B88, 
Type L, Copper Tube 



6 8 10 



0,5 



1.5 



2 2.5 4 

Pipe Size, NPS 



8 10 12 



(b) Thermoplastic Pipe 
[Notes (1) and (2)] 



NOTES: 

(1) Based on pipe at 73°F with water and insulation. Closer spacing required at higher temperatures. 

(2) Use shields on all hangers to avoid point loading of pipe. 



ASME B31.9-2008 



(e) Limitations on Charts. The spans in Figs. 921.1.3-1 
and 921.1.3-2 are based on limitations in paras. 921.1.3(a) 
and (b) and are not applicable where there are concen- 
trated loads, i.e., valves, special fittings, etc. Spans and 
deflections are based on the simple beam formulas lim- 
iting the combined pressure and bending stress to the 
basic allowable stress for the material. 

921.1.4 Springs. Springs used in spring hangers 
shall be designed and manufactured in accordance with 
MSS SP-58. 

921.2 Fixtures 

921.2.1 Anchors and Guides 

(a) Requirements. Anchors, guides, pivots, and other 
restraints shall be designed to secure the piping at their 
respective locations against movement in specified 
planes or directions, while permitting free movement 
elsew T here. They shall be structurally suitable to with- 
stand the thrusts, moments, and other imposed loads. 

(b) Required Guides, Where bellows or slip-type 
expansion joints are used, anchors and guides shall be 
provided to direct expansion movement along the axis 
of the joint. 

(c) Pipe Buckling. The column buckling strength of the 
pipe must be taken into consideration when determining 
guide spacing for expansion joints. This is especially true 
for small diameter lines. Maximum spacing of guides for 
any pipe material or thickness may be calculated using 
eq." (9): 



Table 921.2.2 Capacities of Threaded ASTM A 36 (os) 
Steel Rods 



(U.S. Customary Units) 



L s = 0.131 V 'E WI J/(PB + Q) 



(9) 



(SI Units) 



L s = 0Ml57JE m I/{PB + Q) 



Q is positive for expansion joint compression and nega- 
tive for expansion joint extension. 

(d) Rolling or Sliding Supports. These supports shall 
permit free movement of the piping, or the piping shall 
be designed to include the imposed loads and friction 
forces of the supports. Materials and lubricants used in 
sliding supports shall be suitable for the metal tempera- 
ture at the point of contact. 

921.2.2 Other Rigid Supports 

(a) Hanger Rods. Safe loads for hanger rods shall be 
based on the root area of threads and allowable stress 
for the material. In no case shall hanger rods less than 
7 8 in. (9.5 mm) in diameter be used to support pipe 
NPS lV 2 (DN 40) or larger. See Table 921.2.2 for permissi- 
ble loads on carbon steel rods. 

Pipe, straps, or bars of strength and effective area 
equivalent to hanger rod may also be used. 

(b) Cast Iron. ASTM A 48 cast iron may be used for 
bases, rollers, anchors, and parts of supports where the 



Nominal Rod 


Root Area of 


Maximum Safe 


Diameter, 


Coarse Thread, 


Load, lb 


in. 


in. 2 


(5 = 11.6 ksi) 


% 


0.027 


310 


Vs 


0.068 


790 


y 2 


0.126 


1,460 


% 


0.202 


2,340 


% 


0.302 


3,500 


% 


0.419 


4,860 


i 


0.552 


6,400 


iVs 


0.693 


8,000 


i% 


0.889 


10,300 



loading is primarily in compression. Cast iron parts shall 
not be used in tension. 

(c) Malleable Iron. ASTM A 47 malleable iron may be 
used for pipe clamps, beam clamps, hanger flanges, 
clips, bases, swivel rings, and parts of pipe supports. 

921.2.3 Variable Supports 

(a) Requirements. Variable spring supports shall be 
designed to exert a supporting force equal to the load, 
as determined by weight balance calculations, plus the 
weight of all hanger parts (such as clamp, rod, etc.) 
that will be supported by the spring at the point of 
attachment to the pipe. 

(b) Design. Variable spring supports shall be pro- 
vided with means to limit misalignment, buckling, 
eccentric loading, and overstressing of the spring. It is 
recommended that they be designed for a maximum 
variation in supporting effort of 25% for the total travel 
resulting from thermal movement. 

(c) Indicators. It is recommended that all hangers 
employing springs be provided with means to indicate 
at all times the compression of the spring with respect 
to the approximate hot and cold positions of the pipe 
system, except where they are used either to cushion 
against shock or where the operating temperature of the 
system does not exceed 250°F (121°C). 

9213 Structural Attachments 

921.3.1 NonintegralType. Nonintegral attachments 
include clamps, slings, cradles, saddles, straps, and 
clevises. 

When clamps are used to support vertical lines, they 
shall be designed to support the total load due to weight 
of piping, contained fluid, insulation, and other loads 
such as forces from expansion joints. It is recommended 
that shear lugs or the clamp be welded to the pipe to 
prevent slippage, following the requirements of para. 
921.3.2. 

921.3.2 Integral Type. Integral attachments include 
ears, shoes, lugs, cylindrical attachments, rings, and 
skirts fabricated so as to be an integral part of the piping. 



23 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



ASME B31.9-2008 



When welded to the pipe, materials and procedure shall 
be compatible with the piping and strength shall be 
adequate for all expected loadings. If piping and support 
materials differ in allowable stress, the lower shall gov- 
ern design. 

Integral attachments shall be used in conjunction with 
restraints or braces where multi axial loadings are 
imposed. Design shall consider all imposed weight and 
thermal loadings, and shall minimize localized stresses 
induced in the piping by the attachment. 

921.4 Supplemental Steel 

Where it is required to frame structural members 
between existing steel members, such supplementary 
steel shall be designed using the allowable stress speci- 
fied in para. 921.1.1. 

921.5 Attachments to Concrete 

921.5.1 Maximum Loads on Attachments, Loads on 
anchors, cast-in-place inserts, and other attachments to 
concrete shall not exceed one-fifth of the ultimate 
strength of the attachment as determined by manufac- 
turer's tests in concrete of compressive strength not 
greater than that in which the attachment will be used, 
but at least 2,500 psi (17.2 MPa). 

If the compressive strength of the concrete is unknown, 
it shall be assumed to be 2,500 psi (17.2 MPa) and the 
manufacturer's rated load for the fastener shall be 
reduced in the ratio of 2,500 psi (17.2 MPa) to the strength 
used in the tests to determine the rating. 

In the absence of manufacturer's ratings, the attach- 
ment may be tested for ultimate strength in accordance 
with ASTM E 488. 

921.5.2 Expansion Studs and Anchors. Mechani- 
cally attached concrete or masonry anchors shall extend 
into the concrete at least the minimum distance recom- 
mended by the manufacturer; use a length at least 4% 
times the fastener diameter in the absence of such recom- 
mendation, 

If multiple anchors are required to hold a load, they 
must be spaced at least eight diameters on center to 
realize the full design capacity of each anchor. 

921.5.3 Concrete Inserts. Placing of inserts shall be 
in accordance with the manufacturer's recommenda- 
tions. 

921.5.4 Explosive Actuated Fasteners. Explosive 
actuated fasteners shall not be used where a group of 
fasteners is necessary to support the total load. 

921.5.5 Split Pin Compression Anchors. Split pin 
compression anchors shall be used only for shear loads. 

921.6 Supporting Structures 

The engineer shall assure himself that the supporting 
structure has adequate strength to sustain all loads 
imposed by the piping. 



PART 6 
SYSTEMS 

922 DESIGN REQUIREMENTS PERTAINING TO 
SPECIFIC PIPING SYSTEMS 

922.1 Pressure Reducing Systems 

922.1.1 General. Where pressure reducing valves 
are used, a relief device or safety valve shall be provided 
on the low pressure side of the system. Otherwise, the 
piping and equipment on the low side of the system shall 
be designed to withstand the upstream design pressure. 
The relief or safety devices shall be located adjoining 
or as close as practicable to the reducing valve. The 
combined relieving capacity provided shall be such that 
the design pressure of the low pressure system will not 
be exceeded if the reducing valve fails to open. 

922.1.2 Alternative Systems. In steam systems 
where the use of relief valves as described in para. 922.1.1 
is not feasible (e.g., because there is no acceptable dis- 
charge location for the vent piping), alternative designs 
may be substituted for the relief devices. In either case, 
it is recommended that alarms be provided that will 
reliably warn the operator of failure of any pressure 
reducing valve. 

(a) Tandem Steam. Pressure Reducing Valves. Two or 
more steam pressure reducing valves may be installed 
in series, each set at or below the safe working pressure 
of the equipment served. In this case, no relief device 
is required. 

Each pressure reducing valve shall have the capability 
of closing off against full line pressure, and of controlling 
the reduced pressure at or below the design pressure of 
the low pressure system, in the event that the other valve 
fails to open. 

(b) Trip Stop Valves. A trip stop steam valve set to 
close at or below the design pressure of the low pressure 
system may be used in place of a second reducing valve 
or a relief valve. 

922.1.3 Bypass Valves. Hand controlled bypass 
valves having a capacity no greater than the reducing 
valve may be installed around pressure reducing valves 
if the downstream piping is protected by relief valves 
as required in para. 922.1.1, or if the design pressure of 
the downstream piping system and equipment is at least 
as high as the upstream pressure. 

922.1.4 Design of Valves and Relief Devices. Pres- 
sure reducing and bypass valves, and relief devices, shall 
be designed for inlet pressure and temperature condi- 
tions. 

922.2 Steam Trap Piping 

922.2.1 Drip Lanes. Drip lines from steam headers, 
mains, separators, heaters, or other equipment that oper- 
ate at differing pressures shall not be connected to dis- 
charge through the same trap. 



24 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



ASME B31.9-2008 



922.2.2 Discharge Piping. Trap discharge piping 
shall be designed for the same pressure and temperature 
as the inlet piping unless the discharge is vented to 
atmosphere, or is operated under low pressure and has 
no stop valves. 

9223 Fuel Oil Piping 

922.3.1 Pipe Material 

(a) Pipe in buildings shall be steel pipe of a material 
listed in Table 926.1 except as permitted in para. 
922.3.1(b). Type F furnace butt welded pipe shall not be 
used w T here concealed. I.e., in walls, chases, shafts, or 
above ceilings. Spiral welded, pipe shall not be used. 

(b) Type L copper tubing may be used in buildings 
if protected from exposure to fire. 

(c) Underground piping may be steel, Type K copper 
tubing, aluminum, ductile iron, thermoplastic, or 



reinforced thermoplastic resin piping. Buried pipe and 
fittings shall be protected against corrosion. 

9223.2 Joints 

(a) Threaded, welded, brazed, or flared joints shall be 
used within buildings. A pipe thread compound suitable 
for oil shall be used on threaded joints. Joints relying 
on friction or a combustible material shall not be used. 
Brazing or flare fittings shall be wrought. Flanged or 
grooved joints may be used with a gasket material meet- 
ing the requirements of API 607 or another standard 
acceptable to the owner. 

(b) For underground piping, friction type joints and 
grooved joints may also be used. 

92233 Valves. At the point of entry of under- 
ground piping to the building, an accessible steel or 
ductile iron valve shall be installed to control the flow 
of oil. 



25 



Copyright © 2008 by the American Society of Mechanical Engineers. (hgsA 

No reproduction may be made of this material without written consent of ASME. ^ 



ASME B31. 9-2008 



Chapter III 
Materials 



923 MATERIALS - GENERAL REQUIREMENTS 

Chapter III states limitations for materials, based on 
their inherent properties. Their use in piping is also 
subject to requirements and limitations in other parts of 
this Code. 

923.1 Materials and Specifications 

923.1.1 Listed or Published Specifications. Any 

material used in pressure containing piping components 
shall conform to a specification listed in Mandatory 
Appendix I, or to a published specification in accordance 
with para. 923.1.2. 

923.1.2 Materials Not Listed. Allowable stresses for 
materials not shown in Mandatory Appendix I, but 
which are shown in ASME B31.1, may be taken from 
Mandatory Appendix I of ASME B31.1. 

A material not listed in this Code nor in ASME B31.1, 
but which conforms to a published specification cov- 
ering composition, physical and mechanical properties, 
method and process of manufacture, heat treatment (if 
applicable), and quality control may be used if it other- 
wise meets the requirements of this Code. Allowable 
stresses for such materials shall be determined in accor- 
dance with the applicable basis in para. 902.3.1, or a 
more conservative basis. Particular attention should be 
given to properties that may affect weld ability or ductil- 
ity adversely 

923.1.3 Used Materials. Used pipe and other com- 
ponents of known specifications may be employed pro- 
vided they have been thoroughly cleaned and visually 
inspected (and tested if applicable) to determine that 
they are in good condition, meet the applicable dimen- 
sional requirements, and do not contain defects that 
could impair strength or tightness or that are not accept- 
able under this Code. 

923.1.4 Limitations on Unknown Materials. Steel of 
unknown specification shall be used only for structural 
supports and restraints. 

923.2 Limitations on Specific Metals 

923.2.1 Cast Iron. The low ductility of cast iron 
should be considered and its use should be avoided 
where shock loading may occur. 

923.2.2 Ductile iron. Ductile (nodular) cast iron 
components having dimensions conforming to ASME 



B16.3, ASME B16.4, or ASME B16.5 may be used in 
accordance with the manufacturer's pressure-tempera- 
ture ratings. Welding shall not be used as a method of 
joining ductile iron components. 

923.2.3 Copper and Copper Alloys. Consideration 
should be given to the melting point of copper in flam- 
mable fluid service. 

923.2.4 Aluminum and Aluminum Alloys. Consider- 
ation should be given to the melting point of aluminum 
in flammable fluid service. When assembling threaded 
joints in aluminum alloys, a suitable thread compound 
shall be used to prevent seizing. Pipe in the annealed 
temper should not be threaded. 

923.3 Limitations on Specific Nonmetals 

923.3.1 General. Nonmetallic pressure containing 
components, such as glass, ceramics, plastics, or rubber, 
may be used within the limitations of para. 923.1.2 and 
within manufacturers' limitations on pressure-tempera- 
ture ratings and application. Consideration shall be 
given to the suitability of the material for the service 
conditions and the fluid to be handled, its flammability, 
resistance to shock, its dimensional stability, and proper 
support and protection from damage. 

923.3.2 Thermoplastics. Thermoplastics shall not 
be used for toxic fluids or oxygen. They shall not be 
used for flammable liquids or flammable gases above 
ground. If thermoplastics are used for compressed air 
or other compressed gases, special precautions must be 
observed. The stored energy and specific failure mecha- 
nism of the pipe need to be considered. Materials such 
as PVC, CPVC, and PVDF, which exhibit brittle failure 
as defined in ASTM F 412, shall not be used for com- 
pressed air or gas service. 

Consideration shall be given to the brittleness and 
flammability of thermoplastics and to their loss of 
strength under only slight increases in temperature. In 
selecting thermoplastics, note that design properties are 
subject to considerable variation from one type and 
grade to another. 

923.3.3 Reinforced Thermosetting Resin. In select- 
ing reinforced thermosetting resin (RTR) piping, note 
that design properties are subject to considerable varia- 
tion from one type and grade to another. Consideration 
shall be given to the flammability of RTR piping and 
its susceptibility to brittle failure. 



26 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



ASME B31.9-2008 



9233.4 Composite /Materials. Composite materials 
shall be selected to conform to ASTM and manufactur- 
er's recommendation for pressure temperature, support, 
and service conditions. 

923.4 Coatings and Linings 

External coatings or internal linings may be used on 



of this Code, but such coatings or linings shall not be 
considered as adding strength. 

923.5 Deterioration in Service 

It is the responsibility of the engineer to select materi- 
als that will resist deterioration in service, or to make 
allowances for such deterioration in accordance with 



pipe or components that conform to the requirements para. 902.4.1. 



27 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



ASME B31.9-2008 



Chapter IV 
Component Requirements and Standard Practices 



926 DIMENSIONS AND RATINGS OF 
COMPONENTS 

926.1 Standard Piping Components 

Standard piping components shall conform to one of 
the standards or specifications listed in Table 926.1. 
Those listed in ASME B31.1 may also be used. 

926.1.1 Boiler External Piping. Materials used in 
boiler external piping shall be ASME SA or SB specifica- 
tions corresponding to the ASTM specifications listed 
in Table 926.1. 

926.2 Standard Practices 

The standards listed in Table 926.2 should be used 
for design and installation where applicable under this 
Code. 

926.3 Nonstandard Piping Components 

When nonstandard piping components are used, pres- 
sure design shall be in accordance with para. 904. Adher- 
ence to the dimensional principles in American National 
Standards referenced in Table 926.1 is recommended to 
the greatest practicable extent. 

926.4 Abbreviations 

Abbreviations used in Tables 926.1 and 926.2 signify 
the following: 



Abbreviation 


Term 




General 


BW 


butt-welding 


CI 


cast iron 


DI 


ductile iron 


HT 


high temperature 


LT 


low temperature 


MI 


malleable iron 


SS 


stainless steel 


sw 


socket- welding 


Thd 


threaded 


TS 


tensile strength 




Plastics 


ABS 


acrylonitrile-butadiene-styrene 


CPVC 


chlorinated polyvinyl chloride 


PB 


polybutylene 


PE 


polyethylene 


PEX 


crosslinked polyethylene 


PP 


polypropylene 


PR 


pressure rating 


PVC 


polyvinyl chloride 


RTP 


reinforced thermosetting plastic 


RTR 


reinforced thermosetting resin 


SDR 


standard dimension ratio 




Composites 


PE-AL-PE 


polyethylene-aluminum- 




polyethylene 


PEX-AL-PEX 


crosslinked poly e thy lene- 




aluminum-crossl inked 




polyethylene 



28 



Copyright © 2008 by the American Society of Mechanical Engineers. ^L sj 

No reproduction may be made of this material without written consent of ASME. ^ 



ASME B31.9-2008 



Table 926.1 Component Standards and Specifications 



Component Designation 



Metallic Pipe, Fittings, Valves, and Flanges 

American Petroleum Institute (API) 

Line Pipe 5L 

Wafer Check Valves 594 

Butterfly Valves, Lug-Type and Wafer-Type 609 

The American Society of Mechanical Engineers (ASME) 

Cast Iron Pipe Flanges and Flanged Fittings B16.1 

Malleable Iron Threaded Fittings, Classes 150 and 300 . B16.3 

Cast Iron Threaded Fittings, Classes 125 and 250 B16.4 

Pipe Flanges and Flanged Fittings B16.5 

Factory-Made Wrought Steel BW Fittings B16.9 

Face-to-Face and End-to-End Dimensions of Ferrous Valves B16.10 

Forged Steel Fittings, Socket-Welding and Threaded B16.ll 

Ferrous Pipe Plugs, Bushings, and Locknuts With Pipe Threads B16.14 

Cast Bronze Threaded Fittings, Classes 125 and 250 . B16.15 

Cast Copper Alloy Solder Joint Pressure Fittings B16.18 

Wrought Copper and Copper AStoy Solder joint Pressure Fittings B16.22 

Bronze Pipe Flanges and Flanged Fittings, Classes 150 and 300 B16.24 

Cast Copper Alloy Fittings for Flared Copper Tubes B16.26 

Wrought Steel Buttwelding Short Radius Elbows and Returns B16.28 

Manually Operated Metallic Gas Valves for Use in Gas Piping Systems Up to 125 psig (Sizes l / 2 Through 2) B16.33 

Valves, Flanged, Threaded, and Welding End B16.34 

Orifice Flanges B16.36 

Malleable Iron Threaded Pipe Unions, Classes 150, 250, and 300 B16.39 

Ductile Iron Pipe Ranges and Ranged Fittings, Classes 150 and 300 B16.42 

Welded and Seamless Wrought Steel Pipe B36.10M 

Stainless Steel Pipe B36.19M 

Society of Automotive Engineers (SAE) 

Refrigeration Tube Fittings J513 

American Society for Testing and Materials (ASTM) 

Ferritic Malleable Iron Castings A 47 

Gray Iron Castings A 48 

Pipe, Steel, Black and Hot-Dipped, Zinc Coated Welded and Seamless A 53 

Forgings, Carbon Steel, for Piping Components A 105 

Seamless Carbon Steel Pipe for HT Service A 106 

Gray Iron Castings for Valves, Flanges, and Pipe Fittings A 126 

Electric-Resistance-Welded Steel Pipe A 135 

Forgings, Carbon Steel for General Purpose Piping A 181/A 181M 

Cupola Malleable iron A 197 

Spiral-Welded Steel or iron Pipe A 211 

Piping Fittings of Wrought Carbon Steel and Alloy Steel for Moderate and Elevated Temperatures A 234/A 234M 

Copper Brazed Steel Tubing A 254 

Gray Iron Castings for Pressure-Containing Parts for Temperatures up to 650°F (345°C) A 278/A 278M 

Seamless and Welded Austenitic Stainless Steel Pipes A 312/A 312M 

Ductile iron Pressure Pipe A 377 

Ferritic Ductile Iron Pressure-Retaining Castings for Use at Elevated Temperatures A 395/A 395M 

Wrought Austenitic SS Piping Fittings A 403/A 403M 

Ductile Iron Castings A 536 



29 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of AS'ME. 



ASME B31.9-2008 



(08) Table 926.1 Component Standards and Specifications (Cont'd) 

Component 
Metallic Pipe, Fittings, Valves, and Flanges (Cont'd) 

American Society for Testing and Materials (ASTM) (Cont'd) 

Electric-Resistance-Welded Coiled Steel Tubing for Gas and Fuel Oil Lines 

Aluminum-Alloy Sand Castings 

Seamless Copper Pipe, Standard Sizes 

Seamless Red Brass Pipe, Standard Sizes 

Steam or Valve Bronze Castings 

Composition Bronze or Ounce Metal Castings 

Seamless Copper Tube, Bright Annealed 

Seamless Copper Tube 

Seamless Copper Water Tube 

Seamless Brass Tube [Note (1)] 

Aluminum-Alloy Drawn Seamless Tubes 

Aluminum-Alloy Seamless Pipe and Seamless Extruded Tube 

Aluminum and Aluminum-Alloy Die, Hand, and Rolled Ring Forgings 

General Requirements for Wrought Seamless Copper and Copper-Alloy Tube 

Seamless Copper Tube for Air Conditioning and Refrigeration Field Service 

Copper and Copper-Alloy Die Forgings (Hot-Pressed) 

Threadless Copper Pipe 

Factory-Made Wrought Aluminum and Aluminum-Alloy Welding Fittings 

Aluminum-Alloy Formed and Arc Welded Round Tube 

American Water Works Association (AWWA or ANSI/AWWA) 

Ductile Iron and Gray-Iron Fittings, 3 in. Through 48 in., for Water and Other Liquids 

Ductile Iron Pipe Centrifugally Cast in Metal Molds or Sand-Lines Molds, for Water and Other Liquids 

Steel Pipe Flanges for Waterworks Service — Sizes 4 in. Through 144 in 

Dimensions for Fabricated Steel Water Pipe Fittings 

Gate Valves for Water and Sewage Systems 

Grooved and Shouldered Type joints 

Federal Government 
Pipe, Cast Iron and Ductile Iron (Pressure, for Water and Other Liquids) 

Manufacturers Standardization Society of the Valve and Fittings Industry (MSS) 

Class 150 Corrosion Resistant Gate, Globe, Angle, and Check Valves With Flanged and Butt Weld Ends 

Wrought Stainless Steel Butt Weld Fittings , 

By-Pass and Drain Connection Standard 

Class 150 LW Corrosion Resistant Cast Flanges and Flanged Fittings 

Butterfly Valves 

Cast Iron Gate Valves, Flanged and Threaded Ends 

Cast Iron Swing Check Valves, Flanged and Threaded Ends 

Ball Valves With Flanged or Butt Weld Ends for General Service 

Cast Iron Plug Valves, Flanged and Threaded Ends 

SW Reducer Inserts 

Bronze Gate, Angle, and Check Valves 

Carbon Steel Pipe Unions — SW and Thd 

Cast Iron Globe and Angle Valves, Flanged and Thd Ends 

Diaphragm Type Valves 

Ball Valves Threaded, Socket-Welding, Solder joint, Grooved and Flared Ends [Note (2)] 



Designation 



A 539 

B 26/B 26M 

B 42 

B 43 

B 61 

B 62 

B 68/B 68M 

B 75/B 75M 

B 88/B 88M 

135/B 135M 

210/B 210M 

241/B 241M 

247/B 247M 

251/B 251M 

B 280 

B 283 

B 302 

B 361 

B 547 



C110/A21.10 
C151/A21.51 
C207 
C208 
C500 
C606 



FS WW-P-421 



SP-42 
SP-43 
SP-45 
SP-51 
SP-67 
SP-70 
SP-71 
SP-72 
SP-78 
SP-79 
SP-80 
SP-83 
SP-85 
SP-88 
SP-110 



30 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



ASME B31.9-2008 



Table 926.1 Component Standards and Specifications (Cont'd) 

Component 
Nonmetallic Pipe, Composite Pipe, Fittings, Valves, and Flanges 

American Society for Testing and Materials (ASTM) 

Reinforced Concrete Low-Head Pressure Pipe 

Contact-Molded Reinforced Thermosetting Plastic (RTP) Laminants for Corrosion Resistant Equipment 

ABS Plastic Pipe, Schedules 40 and 80 

PVC Plastic Pipe, Schedules 40, 80, and 120 , 

PE Plastic Pipe, Schedule 40 

PE Plastic Pipe (SIDR-PR) Based on Controlled Inside Diameter 

PVC Pipe Pressure Rated Pipe (SDR- Series) 

ABS Plastic Pipe (SDR-PR) 

Classification for Machine-Made RTR Pipe 

PE Plastic Pipe, Schedules 40 and 80 Based on Outside Diameter 

Threaded PVC Plastic Pipe Fittings, Schedule 80 

PVC Plastic Pipe Fittings, Schedule 40 

Socket-Type PVC Plastic Pipe Fittings, Schedule 80 

ABS Plastic Pipe Fittings, Schedule 40 

Thermoplastic Gas Pressure Pipe Tubing and Fittings 

Reinforced Epoxy Resin Piping Gas Pressure Pipe and Fittings 

Plastic insert Fittings for PE Plastic Pipe 

PB Plastic Pipe (SIDR-PR) Based on Controlled Inside Diameter 

PB Plastic Tubing 

joints for IPS PVC Using Solvent Cement 

Socket-Type PE Fittings for Outside Diameter-Controlled PE Pipe and Tubing 

PE Plastic Tubing 

CPVC Plastic Hot- and Cold-Water Distribution Systems 

Filament-Wound RTR Pipe 

Centrifugally Cast Glass Fiber RTR Pipe 

PB Plastic Pipe (SDR-PR), Based on Outside Diameter 

PE Plastic Pipe (SDR-PR), Based on Controlled Outside Diameter 

Butt Heat Fusion PE Plastic Fittings for PE Plastic Pipe and Tubing 

Biaxially Oriented PE (PEO) Plastic Pipe (SDR-PR) Based on Controlled Outside Diameter 

PB Plastic Hot- and Cold-Water Distribution Systems 

Specification for "Fiberglass" (Glass-Fiber-Reinforced-Thermosetting Resin) Pressure Pipe 

Specification for Fiberglass Sewer and Industries Pressure Pipe. 

Specification for Reinforced Plastic Mortar Pipe Fittings for Non-Pressure Applications 

Threaded CPVC Plastic Pipe Fittings, Schedule 80 

Socket-Type CPVC Plastic Pipe Fittings, Schedule 40 

Socket-Type CPVC Plastic Pipe Fittings, Schedule 80 ... 

CPVC Plastic Pipe, Schedules 40 and 80 

CPVC Plastic Pipe (SDR-PR) 

Standard Specification for Crosslinked Polyethylene (PEX) Tubing 

Standard Specification for Crosslinked Polyethylene (PEX) Plastic Hot- and Cold-Water Distribution Systems 

Standard Specification for Crosslinked Polyethylene/Aluminum/Crosslinked Polyethylene (PEX-AL-PEX) Pressure Pipe 

Standard Specification for Polyethylene/Aluminum/Polyethylene (PE-AL-PE) Composite Pressure Pipe 

Standard Specification for Pressure-Rated Composite Pipe for Elevated Temperature Service 

Standard Specification for Cold-Expansion Fittings With Metal Compression-Sleeves for Cross-Linked Polyethylene 

(PEX) Pipe 

American Water Works Association (AWWA or ANSI/AWWA) 

Reinforced Concrete Pressure Pipe, Steel Cylinder Type, for Water and Other Liquids 

Prestressed Concrete Pressure Pipe, Steel Cylinder Type, for Water and Other Liquids 

Reinforced Concrete Pressure Pipe, Noncylinder Type, for Water and Other Liquids 

PVC Pressure Pipe, 4 in. Through 12 in., for Water 



(08) 



Designation 



C 361/C 361M 
C 582 
D 1527 
D 1785 
D 2104 
D 2239 
D 2241 
D 2282 
D 2310 
D 2447 
D 2464 
D 2466 
D 2467 
D 2468 
D 2513 
D 2517 
D 2609 
D 2662 
D 2666 
D 2672 
B 2683 
D 2737 
D 2846 
D 2996 
D 2997 
D 3000 
D 3035 
D 3261 
D 3287 
D 3309 
D 3517 
D 3754 
D 3840 
F437 
F438 
F439 
F441 
F442 
F876 
F877 
F1281 
F1282 
F1335 

F2080 



C300 
C301 
C302 
C900 



31 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



ASME B31.9-2008 



(08) Table 926.1 Component Standards and Specifications (Cont'd) 

Component Designation 

Miscellaneous Components 

The American Society of Mechanical Engineers (ASME) 

Unified Screw Threads Bl.l 

Pipe Threads (Except Dryseal) Bl.20,1 

Dryseal Pipe Threads Bl.20.3 

Hose Coupling Screw Threads Bl.20.7 

Nonmetallic Flat Gaskets for Pipe Flanges B16.21 

Buttwelding Ends for Pipe, Valves, Flanges, and Fittings B16.25 

Square and Hex Bolts and Screws B18.2,l 

Square and Hex Nuts B18.2.2 

American Society for Testing and Materials (ASTM) 

Structural Steel A 36/A 36M 

Carbon Steel Track Bolts and Nuts A 183 

Alloy-Steel and SS Bolting Materials for HT Service A 193/A 193M 

Carbon and Alloy Steel Nuts for Bolts for High Pressure and HT Service A 194/A 194M 

Carbon Steel Bolts and Studs, 60,000 PS! Tensile A 307 

Solder Metal B 32 

Threads (60-Deg. Stud) for Glass RTR Pipe D 1694 

Solvent Cement for ABS Plastic Pipe and Fittings D 2235 

Solvent Cements for PVC Plastic Pipe and Fittings D 2564 

Solvent Cements for Transition joints Between ABS and PVC Non-Pressure Piping Components D 3138 

Joints for Plastic Pressure Pipes Using Flexible Elastometric Seals D 3139 

Solvent Cements for CPVC Plastic Pipe and Fittings F 493 

American Water Works Association (AWWA or ANSI/AWWA) 

Rubber-Gasket joints for Dl and Gray-Iron Pressure Pipe and Fittings C 111/A21.11 

American Welding Society (AWS or ANSl/AWS) 

Covered Carbon Steel Arc Welding Electrodes A5.1 

Iron and Steel Oxyfuel Gas Welding Rods A5.2 

Aluminum and Aluminum Alloy Electrodes for Shielded Metal Arc Welding A5.3 

Covered Corrosion-Resisting Chromium and Chromium-Nickel Steel Welding Electrodes A5.4 

Low Alloy Steel Covered Arc Welding Electrodes A5.5 

Covered Copper and Copper Alloy Arc Welding Electrodes. A5.6 

Copper and Copper Alloy Bare Welding Rods and Electrodes A5.7 

Brazing Filler Metal A5.8 

Corrosion-Resisting Chromium and Chromium-Nickel Steel Bare and Composite Metal 

Cored and Stranded Welding Electrodes and Welding Rods A5.9 

Aluminum and Aluminum Alloy Bare Welding Rods and Electrodes A5.10 

Tungsten Arc Welding Electrodes (Non-Consumable) A5.12 

Carbon Steel Electrodes and Fluxes for Submerged Arc Welding A5.17 

Carbon Steel Filler Metals for Gas Shielded Arc Welding A5.18 

Carbon Steel Electrodes for Flux Cored Arc Welding A5.20 

Flux Cored Corrosion-Resisting Chromium and Chromium-Nickel Steel Electrodes A5.22 

Low Alloy Steel Electrodes and Fluxes for Submerged Arc Welding A5.23 

Manufacturers Standardization Society of the Valve and Fittings Industry (MSS) 

Standard Finishes for Contact Faces of Pipe Flanges and Connecting-End Flanges of Valves and Fittings SP-6 

Standard Marking System for Valves, Fittings, Flanges, and Unions SP-25 

Pipe Hangers and Supports — Materials, Design, and Manufacture SP-58 

Society of Automotive Engineers (SAE) 

Hydraulic Tube Fittings J514 

GENERAL NOTE: The approved years of issue of standards and specifications listed in this Table are given in Mandatory 

Appendix III. 

NOTES: 

(1) Applicability limited to alloy UNS No. C23000. 

(2) See para. 923.1.2 for permissible materials. 



32 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



ASME B31.9-2008 



Table 926.2 Standard Practices (os) 



Component Designation 



American Petroleum Institute (API or ANSI/APS) 

Fire Test for Soft-Seated Quarter-Turn Valves, Fourth Edition , 

American Society for Testing and Materials (ASTM) 

Standard Practice for Making Capillary joints by Soldering of Copper and Copper Alloy Tube and Fittings 

Test Methods for Flash Point by Pensky-Martens Closed Tester 

Test Method for Time-to-Failure of Plastic Pipe Under Constant Internal Pressure 

Test Method for Cyclic Pressure Strength of RTP Pipe 

Practice for Heat joining of Polyolefin Pipe and Fittings 

Practice for Underground Installation of Thermoplastic Pressure Piping 

Method for Obtaining Hydrostatic Design Basis for Thermoplastic Pipe Materials 

Practice for Making Solvent-Cemented Joints With PVC Pipe and Fittings 

Method for Obtaining Hydrostatic Design Basis for RTR Pipe and Fittings 

Practice for Flaring Polyolefin Pipe and Tubing 

Test Method for Strength of Anchors in Concrete and Masonary Elements 

Practice for Safe Handling of Solvent Cements Used for joining Thermoplastic Pipe and Fittings 

Definition of Terms Relating to Plastic Piping Systems 

Standard Specification for Non-Reinforced Extruded Tee Connections for Piping Applications 

American Water Works Association (AWWA or ANSI/AWWA) 

Thickness Design of Dl Pipe 

Installation of D! Water Mains and Other Appurtenances 

Copper Development Association (CDA) 
Copper Tube Handbook 

Manufacturers Standardization Society of the Valve and Fittings Industry (MSS) 

Pipe Hangers and Supports — Selection and Application SP-69 

Pipe Hangers and Supports — Fabrication and Installation Practices SP-89 

Guidelines on Terminology for Pipe Hangers and Supports SP-90 

GENERAL NOTE: The approved years of issue of standards and specifications listed in this Table are given in Mandatory Appendix ill. 



Std 607-1993 


B 828 


D 93 


D 1598 


D 2143 


D 2657 


D 2774 


D 2837 


D 2855 


D 2992 


D 3140 


E 488 


F402 


F412 


F2014 


C150/A21.50 


C600 



33 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



ASME B31.9-2008 



Chapter V 
Fabrication* Assembly, and Erection 



927 WELDED FABRICATION OF METALS 

927.1 General 

Welding shall be performed in accordance with the 
qualification requirements of para. 927.5. Limitations on 
imperfections and acceptance standards are as stated in 
Chapter VI or in the engineering design. 

927.2 Materials 

927.2.1 Electrodes and Filler Metal. Welding elec- 
trodes and filler metal, including consumable inserts, 
shall conform to the requirements of the ASME BPV 
Code, Section II, Part C. An electrode or filler metal not 
conforming to the above may be used provided the WPS, 
welders, and welding operators who will follow the 
WPS have been qualified as required by ASME BPV 
Code, Section IX. 

Unless otherwise specified by the designer, welding 
electrodes and filler metals used shall produce weld 
metal that complies with the following: 

(a) The nominal tensile strength of the weld metal 
shall equal or exceed the tensile strength of the base 
metals being joined. 

(b) If base metals of different tensile strengths are to 
be joined, the nominal tensile strength of the weld metal 
shall equal or exceed the tensile strength of the weaker 
of the two. 

(c) The nominal chemical analysis of the weld metal 
shall be the same as the nominal chemical analysis of 
the major alloying elements of the base metal. 

(d) If base metals of differing chemical analysis are 
being joined, the nominal chemical analysis of the weld 
metal shall be the same as either base metal or an inter- 
mediate composition, except as specified below for aus- 
tenitic steels joined to ferritic steels. 

(e) When austenitic steels are joined to ferritic steels, 
the weld metal shall have an austenitic structure. 

(f) For nonferrous metals, the weld metal shall be that 
recommended by the manufacturer of the nonferrous 
metal or by industry associations for that metal. 

(g) For unusual materials or combinations of materi- 
als, the design engineer shall specify the weld metal that 
is required. 

927.2.2 Backing Rings. Backing rings are not 
required but when used shall be of a material compatible 
with the base metal and shall fit the inside diameter of 
the pipe. Backing rings may be tacked to the inside of 
the pipe and shall be fused into the root of the weld. 



927.3 Preparation 

927.3.1 Butt and Miter Welds 

(a) End Preparation. End preparation for butt and 
miter joint welds shall be as shown in the welding proce- 
dure specification. The basic bevel angles shown in 
ASME B16.25 may be used. Oxygen or arc cutting is 
acceptable only if the cut is reasonably smooth and true. 
Discoloration that may remain on the flame-cut surface 
is not considered to be detrimental oxidation. 

(b) Cleaning. Weld areas and surfaces shall be clean 
and free from paint, oil, rust, scale, or any other material 
detrimental to the weld or base metal before welding 
begins and shall be kept clean during welding. All slag 
shall be cleaned from flame-cut surfaces. 

(c) Internal Alignment. The prepared ends of piping 
components to be joined shall be aligned as accurately as 
is practicable within commercial tolerances on diameter, 
wall thickness, and out-of-roundness. Alignment shall 
be preserved during welding. 

(d) Spacing. The root opening of the joint shall be as 
given in the welding procedure. 



If fillet welding is used in 



927.3.2 Fillet Welds. 

joining piping components, applicable requirements of 
para. 927.3.1 shall be met in preparing the parts for 
welding. 

927.4 Rules for Welding 

927.4.1 General 

(a) Protection of Work. No welding shall be done if 
there is impingement of rain, snow, sleet, or high wind 
on the w r eld area, or if the weld area is frosted or wet. 

(b) Preheat. Preheating shall be as required by the 
Welding Procedure Specification. 

927.4.2 Butt and Miter Welds 

(a) Tack Welds. Tack w ? elds shall be made by a quali- 
fied welder or shall be removed. Tack welds that have 
cracked shall be removed. Tack w 7 elds shall be made 
with filler metal that is compatible with the first pass 
filler metal and shall be fused with the first pass. 

(b) External Alignment. If the external surfaces of the 
two components are not aligned, the weld shall be 
tapered between the surfaces. 

(c) Joint Design and Fit-Up. Pipe shall be cut, beveled, 
and tack welded, or otherwise held in alignment to pro- 
vide a good fit that will permit full-penetration welding. 



34 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 




ASAAE B31.9-2008 

Fig. 927.43-1 Fillet Weld Size 
Surface of vertical member 



Surface of horizontal member 



Theoretical throat 




Concave 
fillet 
weld 




(a) Equal Leg FiHet Weld [Note (1)3 



Surface of vertical member 



Surface of horizontal member 



Theoretical throat 




Concave 
fillet 
weld 



(b) Unequal Leg Fillet Weld [Mote (2)] 

NOTES: 

(1) The size of an equal leg fillet weld is the length of the largest inscribed isosceles right triangle. (Theoretical throat = 0.707 x size.) 

(2) The size of an unequal leg fillet weld is the leg length of the largest right triangle that can be inscribed within the weld cross section 
[e.g., V 2 in. x % in. (12.7 mm x 19 mm)]. 



(08) 



927 A3 Fillet and Socket Welds 

(a) Welding. The applicable provisions of para. 
927.4.2(a) shall be followed. 

(b) Contour. Fillet and socket welds may vary from 
convex to concave. The size of a fillet weld is determined 
as shown in Fig. 927.4.3-1. 

(c) Details. Minimum fillet welds for slip-on flanges 
and socket welding components are shown in 
Figs. 927.4.3-2 and 927.4.3-3. 

927.4.4 Seal Welds. If seal welding of threaded 
joints is performed, the surfaces shall be cleaned and all 
exposed threads shall be covered by the seal weld. Seal 
welding shall be done by qualified welders. 

927.4.5 Welded Flat Heads. Typical minimum weld 
sizes for attachment of flat heads are shown in 
Fig. 927.4.5-1. Attachment methods shown in 
Fig. 927.4.5-2 are not acceptable. 

927.4.6 Welded Branches 

(a) Branch Connections. Figure 927.4.6-1 illustrates 
welded branch connections with and without added 
reinforcing. No attempt has been made to show all 
acceptable types of constructions. The fact that one type 
of construction is illustrated does not indicate that it is 
recommended over other types not shown. 



(b) Weld Details. Figure 927.4.6-2 shows basic types 
of welds used in fabricating branch connections. The 
locations and minimum sizes of welds shall conform to 
the requirements of this figure. 

(c) Branch Contours. Branch connections (including 
integrally reinforced welding outlet fittings) that abut 
the outside surface of the main pipe wall, or are inserted 
into an opening in the main pipe wall shall have opening 
and branch contours that provide a good fit and that 
will permit a fully penetrated groove weld. 

(d) Reinforcement. In branch connections having rein- 
forcement pads or saddles, the reinforcement shall be 
attached by welds around the branch pipe and the outer 
periphery, as shown in Fig. 927.4.6-1, sketch (b). A vent 
hole shall be provided (at the side, not at the crotch) in 
the ring or saddle to reveal leakage in the weld between 
branch and main and to provide venting during welding 
or heat treatment. Rings or saddles may be made in 
more than one piece if the joints between the pieces have 
adequate strength and if each piece is provided with a 
vent hole. A good fit shall be provided between rings 
or saddles and the parts to which they are attached. 

927.4.7 Structural Attachments and Supports. 

Welds for structural attachments and supports shall be 
fully penetrated groove welds or fillet welds, unless 



35 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



ASME B31.9-2008 



(08) 



Fig. 927.4.3-2 Minimum Weld Size, Setback, and Depth of insertion for Slip-On 

and Socket Weld Flanges 





(a) 



(b) 



a — weld size: the lesser of 1.4T H or the thickness of the hub, but not less than % in. (3 mm) 

b — setback distance: V\ 6 in. (1.5 mm) minimum if a flange face seal weld is not used. If a flange face seal weld is used, the minimum 

shall be that necessary to avoid damage to the gasket surface due to welding. 
c = depth of insertion: minimum of the greater of T n or \ in. (6 mm) 
T„ = nominal wall thickness 

GENERAL NOTES: 

(a) These sketches illustrate some acceptable methods for attachment of slip-on and socket welding flanges. 

(b) Welding of the flange face seal weld is optional unless specified in the engineering design. 

(c) Depth of insertion shown is for illustration only. 



(08) 



Fig. 927.4.3-3 Minimum Welding Dimensions for 
Socket-Welding Components Other Than Flanges 




Vi6 in. (1.6 mm) approximate 
before welding 



a = the greater of 1.1 T n or Vs in. (3.2 mm) 



36 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



ASME B31. 9-2008 



Fig. 927.4.5-1 Acceptable Welds for Flat Heads 



(08) 



Note (1) 



Tmin. 



27"min. jjJ5 deg min. 

T ^ actual thickness 




45 deg min. 



Note (2) 



NOTES: 

(1) Greater of: 2 x required pipe thickness, or 1.25 x actual pipe thickness, but need not exceed required minimum thickness of closure. 

(2) Pipe may project beyond weld. Closure may be beveled (45 deg max.) beyond weld. 



Fig. 927.4.5-2 Unacceptable Welds for Flat Heads 



(08) 



ncomplete penetration 




37 



Copyright © 2008 by the American Society of Mechanical Engineers. X^ sj 

No reproduction may be made of this material without written consent of ASME. ^ 



AS/VIE B31.9-2008 



(08) 



Fig. 927.4.6-1 Typical Weld Branch Connections 





(a) Without Added Reinforcement 



(b) With Added Reinforcement 




(c) Angular Branch Without Added Reinforcement 



(08) 




Fig. 927.4.6-2 Typical Weld Details 

7", 



45 deg min. 



mk^j4m 



Main 




45 deg min. 



V 16 in. to V 8 in. (1.6 mm to 3.2 mm>-^|*- i/ 1fi jn , t0 i /g in> (1>6 mm t0 32 mm) 

(a) Inserted Branch (b) Set-on Branch 

b = the lesser of T n (branch) or V4 in. (6.4 mm) 



38 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



ASME B31.9-2008 



otherwise specified in the engineering design. Attach- 
ment welds shall be made by qualified welders. 

927.4.8 Weld Defect Repairs. Defects in welds shall 
be removed to sound metal. Repair welds are to be made 
in accordance with the procedure used for the original 
welds, or by another welding method only if it is to a 
qualified procedure, recognizing that the cavity to be 
repaired may differ in contour and dimensions from the 
original joint. 

927.5 Qualification 

The employer is responsible for 

(a) the welding performed by personnel of his organi- 
zation 

(b) conducting the qualification tests required to qual- 
ify the Welding Procedure Specification (WPS) used by 
personnel in his organization, except as provided in 
paras. 927.6.1 and 927.6.2 

(c) conducting the qualification tests required to qual- 
ify the welders and welding operators, except as pro- 
vided in para. 927.6.3 

927.6 Qualification Requirements 

Welding Procedure Specifications (WPSs) to be fol- 
lowed in production welding shall be prepared and qual- 
ified; welders and welding operators shall be qualified 
as required by ASME BPV Code, Section IX, except as 
modified by the following: 

927.6.1 Standard Welding Procedures. Standard 
Welding Procedure Specifications (SWPSs) published by 
the American Welding Society and listed in Appendix 
E of ASME BPV Code, Section IX are permitted for 
code construction within the limitations established by 
Article V of ASME BPV Code, Section IX, including 
performing either the demonstration weld described in 
Section IX, QW-500 or by qualifying one welder follow 7 - 
ing each SWPS. 

927.6.2 Procedure Qualification by Others, In order 
to avoid duplication of effort and subject to the approval 
of the owner, WPSs qualified by a technically competent 
group or agency may be used, provided the following 
are met: 

(a) The WPSs meet the requirements of ASME BPV 
Code, Section IX and any additional qualification 
requirements of this Code. 

(b) The employer has qualified at least one welder or 
welding operator following each WPS. 

(c) The employer's business name shall be shown on 
each WPS and on each qualification record. In addition, 
qualification records shall be signed and dated by the 
employer, thereby accepting responsibility for the quali- 
fications performed by others. 

(08) 927.6.3 Performance Qualification by Others. In 

order to avoid duplication of effort and subject to the 



approval of the owner, an employer may accept the 
performance qualification of a welder or welding opera- 
tor made by a previous employer. This acceptance is 
limited to performance qualifications that were made 
on pipe or tube test coupons. The new employer shall 
have the WPS that was followed during qualification or 
an equivalent WPS that is within the limits of the essen- 
tial variables set forth in ASME BPV Code, Section IX. 
An employer accepting such qualification tests shall 
obtain a copy of the performance qualification test 
record from the previous employer. The record shall 
show the name of the employer by whom the welder 
or welding operator was qualified and the date of that 
qualification. Evidence shall also be provided that the 
welder or welding operator has maintained qualification 
in accordance with QW-322 of Section IX of the ASME 
Boiler and Pressure Vessel Code except that this evidence 
may be provided by an employer responsible for the 
individual's welding performance, even if not the origi- 
nal qualifying employer. The new employer's business 
name shall be shown on the qualification record, and 
it shall be signed and dated by the employer, thereby 
accepting responsibility for the qualifications performed 
by others. 

927.6.4 Qualification Records* The employer shall 
maintain copies of the procedure and performance quali- 
fication records specified by ASME BPV Code, Section 
IX that shall be available to the owner or the owner's 
agent and the Inspector at the location where welding 
is being done. 

928 BRAZING AND SOLDERING OF METALS 

928.1 Brazing 

928.1.1 Brazing Materials 

(a) Filler Metal The brazing filler metal shall conform 
to an applicable AWS classification. 

(b) Flux. When required, fluxes shall be compatible 
with the materials brazed and with the filler metal used. 
Flux residue should be removed when joints are 
completed. 

928.1.2 Preparation and Technique. The technique 
for brazing in the Copper Tube Handbook of the Copper 
Development Association shall be followed. 

928.1.3 Brazing Qualification. Brazing procedure 
and performance qualification are not required. If quali- 
fication is specified in the engineering design, the 
requirements in the ASME BPV Code, Section IX are 
acceptable. 

928.2 Soldering 

928.2.1 Materials 

(a) Filler Metal Filler metal shall conform to the appli- 
cable ASTM specification. Solder shall melt and flow 7 
freely within the specified temperature range. 



39 



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No reproduction may be made of this material without written consent of ASME. 



ASME B31.9-2008 



(b) Flux. Flux should be used to prevent oxidation 
during soldering and to promote surface wettability. 

(08) 928.2.2 Preparation and Technique. The technique 
for soldering in ASTM B 828, "Standard Practice for 
Making Capillary Joints by Soldering/' shall be fol- 
lowed. 



929 BENDING 

929.1 General 

Pipe may be bent to any radius by any hot or cold 
method that results in a bend surface free of cracks and 
substantially free of buckles. Such bends shall meet the 
design requirements of para. 904.2.1. This shall not pro- 
hibit the use of creased or corrugated bends if specified 
in the engineering design. 

930 FORMING 

930.1 General 

Piping components may be formed (by swaging, lap- 
ping, or upsetting of pipe ends, by extrusion of necks, 
etc.) by any suitable hot or cold method that results in 
formed surfaces that conform to specified dimensions 
and are uniform and free of cracks and tears. 

930.2 Mechanically Formed Extruded Outlets in 
Copper Tube 

(a) Mechanically formed extruded outlets shall be 
perpendicular to the axis of the run tube (header). They 
shall be formed by drilling a pilot hole and drawing out 
the tube surface to form a collar having a height of not 
less than three times the thickness of the branch wall. 
The collaring device shall be such as to assure proper 
assembly of the joint. 

(b) The inner branch tube end shall conform to the 
shape of the inner curve of the run tube. Insertion of 
the branch tube shall be controlled to assure alignment 
with specified depth into the collar without extending 
into the flow stream so as to provide internal reinforce- 
ment to the collar. 

(c) Branches can be formed up to the run tube size 
as shown in ASTM F 2014. Forming procedures shall be 
in accordance with the tool manufacturer's recommen- 
dations. 

(d) All joints shall be brazed in accordance with 
para. 928.1. 

(e) The allowable pressure for the joint shall be the 
lowest value calculated by eqs. (10), (11), or (12). 



2S b T b 
D b 



(12) 



p = 



S[D b T nt + 5.00 (T b + T m )] 

D fi (D m + 2.5) 

2sT 
D m 



(10) 



(11) 



where 

D b = branch tube outside diameter, in. (mm) 
D m = main tube outside diameter, in. (mm) 
S ~ allowable stress of the material, psi (kPa) 
T b = branch tube wall thickness, net of mill toler- 
ance and corrosion, in. (mm) 
T m — main tube wall thickness, net of mill tolerance 
and corrosion, in. (mm) 



931 HEAT TREATMENT 

The materials and material thicknesses permitted 
under this Code do not require heat treatment. If the 
engineering design specifies heat treatment after weld- 
ing, these requirements shall be made part of the Weld- 
ing Procedure Specification. 

934 FABRICATION OF NONMETALS 
934.1 Joining Thermoplastic Piping 

934.1.1 Materials. Adhesives, cements, and sealers 
used to join piping components shall be compatible with 
the materials being joined and shall conform to applica- 
ble ASTM specifications. Joining materials that have 
deteriorated by exposure to air, that are beyond the shelf 
life recommended by the manufacturer, or that will not 
spread smoothly shall not be used. 

934.1.2 Solvent Cemented Joints 

(a) Preparation, PVC and CPVC surfaces to be solvent 
cemented shall be cleaned. Cleaning for ABS shall con- 
form to ASTM. D 2235. Cuts shall be free of burrs. Cir- 
cumferential cuts shall be as square as those obtained 
by use of a saw with miter box. A slight interference 
fit between pipe and fitting socket is preferred, and 
diametral clearance between pipe and entrance of socket 
shall not exceed 0.04 in. (1.0 mm). This fit shall be 
checked before solvent cementing. 

(b) Procedure. Solvent cemented joints shall be made 
in accordance with ASTM D 2855. Solvent cements for 
thermoplastics shall conform to the following 
specifications: 

Material ASTM Specification 



PVC 


D 2564 


CPVC 


D2846 


ABS 


D2235 



Application of cement to both surfaces and assembly 
of the surfaces shall produce a continuous bond and a 
small fillet of cement at the outside of the joint. For 
branch connections not using a tee, a full reinforcement 
saddle with integral branch socket shall be cemented to 
the main pipe over its entire contact surface. In addition, 
the saddle shall be further secured to the main pipe by 



40 



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No reproduction may be made of this material without written consent of ASME. 



ASME B31.9-2008 



wrapping glass fiber tape saturated with epoxy resin 
around the saddle and the circumference of the pipe. 
Solvent cement shall be handled as recommended in 
ASTM F 402. 

934.13 Heat Fusion Joints 

(a) Preparation. Surfaces to be heat fused together 
shall be cleaned free of foreign material and surface film. 
Cuts shall be free from burrs, and circumferential cuts 
shall be as square as those obtained by use of a saw 
with miter box. Fixtures shall be used to align pipe and 
fitting when the joint is made. 

(b) Technique, Fleat fusion joints for polyethylene, 
polypropylene, and other thermoplastics commonly 
joined by heat fusion shall be made in accordance with 
procedures in ASTM D 2657, Techniques I — Socket 
Fusion or II — Butt Fusion, and as recommended by 
the manufacturer. Uniform heating of both surfaces and 
their assembly shall produce a continuous homogeneous 
bond between them and a small fillet of fused material 
at the outside of the joint. Branches shall be made only 
by use of molded fittings. 

934.1.4 Flared Joints and Elastomeric Sealed Joints 

(a) Flared Joints. Flared joints shall be made in accor- 
dance with ASTM D 3140. 

(b) Elastomeric Sealed Joints. Elastomeric sealed joints 
shall be made in accordance with ASTM D 3139. 

934.2 Reinforced Thermosetting Resin Piping joints 

934.2.1 Materials. The provisions of para. 934.1.1 
shall also apply to reinforced thermosetting resin pipe. 

934.2.2 Preparation. Cutting of pipe shall be done 
without chipping or cracking it, particularly the inner 
surface of centrifugally cast pipe. Pipe shall be preheated 
if necessary to comply with the above requirement. Cuts 
shall be free from burrs, and circumferential cuts shall 
be as square as those obtained by use of a saw with 
miter box. For branch connections, holes in the main 
pipe shall be made with a hole saw. Mold release agent 
and other material that would interfere with adhesion 
shall be sanded or otherwise removed from surfaces to 
be cemented. 

934.23 Chemical Setting Adhesive Joints. Chemical 
setting adhesive joints shall be made in accordance with 
the manufacturer's recommendations. Application of 
adhesive to the surfaces and their assembly shall pro- 
duce a continuous bond between them. 

For branch connections, a full reinforcement saddle 
having an integral short length of branch pipe shall be 
used. The branch shall project enough to complete a 
nozzle or to join to the branch pipe. The cut edges of 
the hole in the main pipe shall be sealed with cement 
at the time the saddle is cemented to the main pipe. 

934.2.4 Hand Lay-Up Joints. Application of plies 
of reinforcement saturated with catalyzed resin to the 



surfaces to be joined shall produce a continuous struc- 
ture with them. Cuts shall be sealed to protect the rein- 
forcement from the contents of the pipe. Thickness of 
the laid-up portion shall be at least equal to the pipe 
thickness. 

934.3 Repair of Defective Work 

Defective material, joints, and other workmanship in 
nonmetallic piping that fails to meet the requirements 
of para. 936 and of the engineering design shall be 
repaired by an acceptable method or shall be replaced. 
Repair of defects in plastic piping by use of a patching 
saddle is an acceptable method. 

935 ASSEMBLY 

935.1 General 

The assembly of piping components, either in a shop 
or as field erection, shall be done so that the completely 
erected piping conforms to the requirements of this Code 
and of the engineering design. 

935.2 Bolting Procedure 

935.2.1 Alignment. Flanged joints shall be fitted up 
so that the gasket contact faces, prior to bolting, bear 
uniformly on the gasket, and then shall be made up 
with relatively uniform, bolt stress. 

935.2.2 Gasket Loading. In bolting gasketed 
flanged joints, the gasket shall be uniformly compressed 
in accordance with the design principles applicable to 
the type of gasket used. 

935.2.3 Steel-to-iron Flanged Joints. When bolting 
raised-face steel flanges to flat-face cast iron flanges, 
care shall be used to prevent damage to the cast iron 
flanges. 

935.2.4 Bolt Engagement, All bolts and nuts shall 
be fully engaged. 

935.3 Bell and Spigot Joints 

935.3.1 Caulked Joints. Caulked bell and spigot 
joints shall be assembled using oakum and poured lead 
or other joint compounds suitable for the service. Assem- 
bly of cast iron bell and spigot pressure piping shall 
meet the requirements of ANSI/AWWA C600. 

935.3.2 Elastomeric Joints. Bell and spigot joints 
using elastomeric gaskets shall be assembled in accor- 
dance with the manufacturer's recommendations. 

935.4 Threaded Piping 

935.4.1 Threading. Dimensions of threaded joints 
shall conform to the applicable standard listed in Table 
926.1. Threads shall be clean and free of breaks and tears. 

935.4.2 Joint Compound. Any compound or lubri- 
cant used in threaded joints shall be suitable for the 



41 



Copyright © 2008 by the American Society of Mechanical Engineers. & 

No reproduction may be made of this material without written consent of ASME. ^ 



ASME B31.9-2008 



service conditions, and shall not react unfavorably with 
either the service fluid or the piping materials. 

935.43 Seal Welded Joints. Threaded joints that 
are to be seal welded shall be assembled without thread 
compound. 

935.4.4 Backing Off. Backing off of threaded joints 
to facilitate alignment of the pipe is not permitted. 

935.4.5 Threaded Plastic Pipe. Strap wrenches or 
other full circumference wrenches shall be used to 
tighten threaded joints. Tools and other devices used to 
hold or apply forces shall not leave the surface scored 
or deeply scratched. For RTR piping, threads shall be 
coated with sufficient catalyzed resin to cover the 
threads and completely fill the clearance between pipe 
and fitting. 

935.5 Flare Joints 

Ends of tubing shall be cut square and deburred. No 
scratches, breaks, cracks, or other mars at the sealing 
surface of the flare shall be permitted. 

935.6 Ferrule Bite Joints 

Ends of tubing shall be cut square and deburred. No 
scratches, breaks, or other mars on the outside surface 
of the tubing at the fitting shall be permitted. In tight- 
ening the nut, only sufficient torque shall be used to 
"bite" lightly and uniformly into the tube. 

935.7 Compression Joints 

Ends of tubing shall be cut square and deburred. No 
scratches, breaks, or mars are permitted on the outside 
of the tube at the fitting. 

935.8 Other Mechanical and Proprietary Joints 

Grooved, expanded, rolled, O-ring, clamp, gland, and 
other joints permitted by para. 913 shall be assembled 
in accordance with the manufacturer's instructions. 



935.9 Borosilicate Glass Piping 

Glass-to-glass connections shall be made with clamp 
compression type couplings. Closure pieces should pref- 
erably be furnished to exact dimension. If necessary, pipe 
may be field cut and beaded according to manufacturer 's 
instructions. Beaded-to-plain end connections may be 
made with couplings specially designed for this pur- 
pose. Alignment and support for all glass piping shall be 
verified and adjusted in accordance with manufacturer's 
instructions before joints are tightened, 

935.10 Equipment Connections 

When connections are made to equipment or strain- 
sensitive piping components, care should be taken to 
avoid misalignment which can introduce undesirable 
end reactions. 

935.11 Cold Spring 

Before assembling joints to be cold sprung, supports, 
guides, and anchors shall be examined to verify that 
they will not interfere with desired movement or cause 
undesired movements. The gap or overlap prior to final 
assembly shall be checked and corrected if necessary to 
conform to that shown on the drawing. 

935.12 Valve Installation 

Installation of valves with the stem below the hori- 
zontal is not recommended. 

935.13 Repair of Defective Work 

joints that leak during test shall be tightened within 
limits of procedures or manufacturer's instructions. Do 
not attempt to tighten leaking joints with pneumatic 
test pressure on the system. Joints that cannot be safely 
tightened shall be replaced. Assemblies rejected during 
examination shall be repaired and reassembled or 
replaced. Replace any glass piping component that is 
chipped or scratched. 



42 



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No reproduction may be made of this material without written consent of ASME. 



ASME B31.9-2008 



Chapter VI 
Inspection, Examination, and Testing 



936 INSPECTION AND EXAMINATION 

936.1 General 

Inspection applies to quality assurance functions per- 
formed by the owner, or for the owner by persons other 
than the manufacturer, fabricator, or erector. Examina- 
tion applies to quality control functions performed by 
personnel employed by the manufacturer, fabricator, or 
erector of the piping. 

936.1.1 Quality System Program. A quality system 
program is not required by this Code. If a system is 
required by the engineering design, the program in Non- 
mandatory Appendix A or a similar program acceptable 
to the owner may be used. 

936.2 Required Inspection 

Prior to initial operation, it is the owner's responsibil- 
ity to verify that all required examination and testing 
have been completed and to inspect the piping, or have 
it inspected, to the extent necessary to satisfy himself 
that it conforms to all applicable requirements of this 
Code and the engineering design. 

936.2.1 Access to the Work. The owner and his 
representatives shall have access to any place where 
work concerned with the piping is being performed. 
This includes manufacture, fabrication, assembly, erec- 
tion, examination, and testing of the piping. 

936.2.2 Rights of Owner. The owner and his repre- 
sentatives shall have the right to audit any examinations, 
to inspect the piping using examination methods speci- 
fied in the engineering design, and to review all certifica- 
tions and records. 

936.3 Responsibility for Examination 

Inspection does not relieve the manufacturer, fabrica- 
tor, or erector of responsibility for performing all 
required examinations and preparing suitable records 
for the owner's use. 

936.4 Methods of Examination 

The methods described herein shall be performed by 
competent personnel 

936.4.1 Visual Examination. Visual examination is 
observation of the portions of materials, components, 
joints, supports, and other piping elements that are or 
can be exposed to view before, during, or after manufac- 
ture, fabrication, assembly, or erection. This examination 



includes verification of Code and engineering design 
requirements for materials and components, dimen- 
sions, joint preparation, alignment, joining practices, 
supports, assembly, and erection. 

936.5 Type and Extent of Required Examination 

Unless otherwise specified in the engineering design, 
the type of examination shall be visual examination in 
accordance with the method in para. 936.4.1. 

If the degree of examination and inspection or the 
basis for rejection is to be more rigorous than required 
by this Code, it shall be a matter of prior agreement 
between the fabricator or installer and the purchaser. 

936.6 Acceptance Criteria 

Imperfections or indications revealed by examination 
shall be evaluated in accordance with the following crite- 
ria. They are acceptable unless they exceed the specified 
limitations. Those that exceed the stated limits are 
defects, and the work shall be repaired or replaced in 
accordance with the appropriate requirements in Chap- 
ter V. Acceptance criteria in para. 936.6 not detectable by 
visual examination are included to indicate a minimum 
quality level acceptable under this Code. 

936.6.1 Girth Welds and Groove Welds. Limitations 
on imperfections are as follows. 

(a) Cracks. None permitted. 

(b) Lack of Fusion. The length of unfused areas shall 
not be more than 20% of the circumference of the pipe, 
or of the total length of the weld, and not more than 
25% in any 6 in. (152 mm) of weld. 

(c) Incomplete Penetration. The total joint penetration 
shall not be less than the thickness of the thinner of the 
components being joined, except that incomplete root 
penetration is acceptable if it does not exceed the lesser 
of % 2 in. (1 mm) or 20% of the required thickness, and 
its extent is not more than 25% in any 6 in. (152 mm) 
of weld. 

(d) Undercut and Reinforcement. Undercut shall not 
exceed the lesser of % 2 m - (1 mm) or 12^.% of wall 
thickness. Thickness of weld reinforcement shall not 
exceed % 6 in. (4.8 mm). 

(e) Concave Root. Concavity of the root surface shall 
not reduce the total thickness of the joint, including 
reinforcement, to less than the thickness of the thinner 
of the components being joined. 



43 



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ASME B31.9-2008 



(f) Excess Root Penetration, The excess shall not exceed 
the lesser of % in. (3.2 mm) or 5% of the inside diameter 
of the pipe. 

(g) Weld Surfaces. There shall be no overlaps or abrupt 
ridges and valleys. 

936.6.2 Fillet Welds. Limitations on imperfections 
in fillet socket, and seal welds are the same as in para. 
936.6.1 for cracks, lack of fusion, undercut, and weld 
surfaces. 

936.6.3 Brazed and Soldered Joints. Limitations on 
imperfections in brazed and soldered joints are as 
follows: 

(a) Penetration of filler metal inside the pipe shall not 
exceed 100% of the wall thickness. 

(b) There shall be no visible unfilled joint space. 

(c) There shall be no visible evidence of excessive 
overheating. 

936.6.4 Threaded Joints. Limitations on imperfec- 
tions for ASME Bl.20.1 threaded pipe joints are as 
follows. 

(a) No more than six and no less than two threads 
shall be visible after makeup of the joint. 

(b) There shall be no severe chipping or tearing of 
visible threads. 

936.6.5 Caulked and Leaded Joints. Limitations on 
imperfections in caulked and leaded joints are as 
follows: 

(a) The finished joint shall be within \ in. (6.4 mm) 
of the rim of the bell. 

(b) In the finished joint, the spigot shall be centered 
in the bell within \ in. (3.2 mm). 

(c) The joint shall be made in a continuous pour. 

936.6.6 Flanged Joints. Limitations on imperfec- 
tions in flanged joints are as follows: 

(a) When observed during assembly, the flange faces 
shall be parallel within 1 deg, and the force required to 
align pipe axes shall not exceed 10 ft-lb (14 N-m) per in. 
(25 mm) of nominal pipe diameter. 

(b) Bolts and nuts shall be fully engaged. 

936.6.7 Flared, Ftareless, and Compression Joints. 

Limitations on imperfections in flared, flareless, and 
compression joints are as follows: 

(a) There shall be no cracks in flare or tube end. 

(b) Tube ends shall be cut square (visual). 

(c) Tube ends shall be free of distortion or grooves 
that would hinder assembly or sealing. 

(d) Negligible force shall be required to align ends. 

936.6.8 Mechanical and Proprietary Joints. Imper- 
fections in mechanical and proprietary joints shall be 
within the limitations established by the manufacturer. 

936.6.9 Solvent-Cemented, Adhesive, and Heat- 
Fusion Joints. Limitations on imperfections in solvent- 
cemented, adhesive and heat- fusion joints are as follows: 



(a) Internal protrusion shall not exceed 50% of wall 
thickness for solvent-cemented and 25% for adhesive 
and heat-fusion joints. 

(b) There shall be no visible unfilled or unbonded 
areas. 

936.6.10 Hand Lay-Up Joints. Limitations on imper- 
fections in hand lay-up joints are as follows: 

(a) There shall be no visible evidence of lack of 
bonding. 

(b) The length of the laid-up joint shall be at least the 
lesser of 4 in. (102 mm) or the nominal diameter of 
the pipe. 

(c) The thickness of the laid-up joint shall be at least 
equal to the wall thickness of the thinner pipe. 

937 LEAK TESTING 

937.1 General 

Prior to initial operation, each piping system shall be 
tested for leakage. Hydrostatic testing in accordance 
with para. 937.3 shall be employed if possible. Pneu- 
matic testing may be used in lieu of hydrostatic testing 
only in accordance with the limitations in para. 937.4. 
Initial service testing may be used within the limitations 
of para. 937.5. 

937.2 Preparation for Testing 

937.2.1 Exposure of Joints. All joints including 
welds shall be left uninsulated and exposed for examina- 
tion during the test. 

937.2.2 Temporary Supports. Piping designed for 
vapor or gas may be provided with temporary supports 
if necessary to support the weight of test liquid. 

937.2.3 Expansion Joints. Expansion joints that can- 
not sustain the reactions due to test pressure shall be 
provided with temporary restraint, or they may be iso- 
lated from testing. 

937.2.4 Equipment Not Subject to Testing, Equip- 
ment that is not to be subjected to the test pressure shall 
be isolated from the piping. If a valve is used to isolate 
the equipment, its closure shall be capable of sealing 
against the test pressure without damage to the valve. 
Flanged joints at which blinds are inserted to isolate 
equipment need not be tested. 

937.2.5 Precautions Against Overpressure. If the 

test pressure is to be maintained for a period of time 
during which the test fluid is subject to thermal expan- 
sion or any other source of overpressurizing during the 
test, precautions such as the installation of a relief device 
shall be taken to avoid excessive pressure. 

9373 Hydrostatic Testing 

937.3.1 Test Medium. Water at ambient tempera- 
ture shall be used as the test medium except where there 



44 



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No reproduction may be made of this material without written consent of ASME. vS 



ASME B31.9-2008 



is risk of damage due to freezing. Another liquid may 
be used if it is safe for workmen and compatible with 
the piping. 

937.3.2 Vents and Drains. Vents shall be provided 
at high points in the system to release trapped air while 
filling the system. Drains shall be provided at low points 
for complete removal of the test liquid. 

937.3.3 Preliminary Check. The system shall be 
examined to see that all equipment and parts that cannot 
withstand the test pressure are properly isolated. Test 
equipment shall be examined to ensure that it is tight 
and that low pressure filling lines are disconnected. 

937.3.4 Hydrostatic Test Pressure 

(a) Minimum Pressure. Except as limited in para. 
937.3.4(b), a piping system shall be subjected to a hydro- 
static test pressure which at every point in the system 
is not less than 1.5 times the design pressure. 

(b) Maximum Pressure. The test pressure shall not 
exceed the maximum test pressure for any vessel, pump, 
valve, or other component in the system under test. A 
check shall be made to verify that the stress due to 
pressure at the bottom of vertical runs does not exceed 
either of the following: 

(1) 90% of specified minimum yield strength 

(2) 1.7 times the SE value in Mandatory Appendix I 
(for brittle materials) 

937.3.5 Examination for Leakage. Following the 
application of hydrostatic test pressure for at least 
10 min, examination shall be made for leakage of the 
piping, and at all joints and connections. If leaks are 
found, they shall be eliminated by tightening, repair, or 
replacement, as appropriate, and the hydrostatic test 
repeated until no leakage is found. 

937.4 Pneumatic Testing 

937.4.1 General. Compressed gas poses the risk of 
sudden release of stored energy. For that reason, pneu- 
matic testing shall be used only within the following 
limitations: 

(a) The piping system does not contain cast iron pipe 
or plastic pipe subject to brittle failure. 

(b) The system does not contain soldered or solvent 
cement joints over NPS 2 (DN 50). 

(c) The test pressure does not exceed 150 psig 
(1 034 kPa). 

(d) The system will be used in gas service, or for other 
reasons cannot be filled with water. 



(e) Traces of a test liquid would be detrimental to the 
intended use of the piping. 

937.4.2 Test Medium. The gas shall be nonflamma- 
ble and nontoxic. 

937.4.3 Preliminary Test. Prior to application of full 
pneumatic test pressure, a preliminary test of not more 
than 10 psig (69 kPa) shall be applied to reveal possible 
major leaks. (This preliminary test is not subject to the 
limitations in para. 937.4.1, and may be used in conjunc- 
tion with hydrostatic testing or initial service testing.) 

937.4.4 Pneumatic Test Pressure 

(a) Except as limited in para. 937.4.4(b), the test pres- 
sure shall not exceed 1.25 times the design pressure. 
Pressure shall be applied in several stages, allowing time 
for the system to reach equilibrium at each stage. 

(b) The test pressure shall not exceed the maximum 
allowable pneumatic test pressure for any vessel, pump, 
valve, or other component in the system under test. 

937.4.5 Examination for Leakage. After the prelimi- 
nary test, pressure shall be raised in stages of not more 
than 25% up to full pneumatic test pressure, allowing 
time for equalization of strains and detection of major 
leaks at each stage. Following the application of test 
pressure for at least 10 min, the pressure may be reduced 
to design pressure and examination shall be made for 
leakage of the piping. Leaks may be detected by soap 
bubble, halogen gas, scented gas, test gage monitoring, 
ultrasonic, or other suitable means. If leaks are found, 
pressure shall be vented, appropriate repair or replace- 
ment shall be made, and the pneumatic test repeated 
until no leakage is found. 

937.5 Initial Service Leak Test 

937.5.1 General. For gases and steam and conden- 
sate service not over 15 psig (103 kPa gage), and for 
nontoxic, noncombustible, nonflammable liquids at 
pressures not over 100 psig (689 kPa) and temperatures 
not over 200°F (93°C), it is permissible to conduct the 
system testing with the service fluid as outlined in para. 
937.5.2. 

937.5.2 Service Testing. A preliminary test with air 
at low pressure (para. 937.4.3) may be used. In any event, 
the piping system shall be brought up to operating pres- 
sure gradually with visual examination at a pressure 
between one-half and two-thirds of operating pressure. 
A final examination shall be made at operating pressure. 
If the piping system is free of leaks, it will have met the 
requirements of this paragraph. 



45 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



INTENTIONALLY LEFT BLANK 



46 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME, 



ASME B31.9-2008 



MANDATORY APPENDIX I 
STRESS TABLES 



Table 1-1 begins on following page. 



47 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of AS'ME. 



2 




o 




y 






O 


l-S 


o 


O 


T» 


o- *-*! 


^ 


n 


o 


02- 




cr 


o 




B 


© 


ES 


K> 


v: 


O 


cr 


o 


B 


5- 


8 

9* 


Ff 


o> 


<X> 


o 


fr 


Bt 


ft 


W3 


3. 


B 








8 


5/2 
O 


gL 


o 


£ 


a 

<$ 


& 


o 


o 


"-*> 


& 


2 


S 


■CD 

& 


£ 


sa 


8 


B. 


o 


Sa 


o 


■ — l 


t* 


frl 


t/5 


n 


3 


(FP 




B 


o 


<T> 


> 




OP 






^\. 




)^* 


*C 





Table 1-1 Allowable Stresses 



QO 









Type or 








Factor 


Strengths 




Max. Allowable Stress Val 
csi, for Metal Temperature, 


ue in Tension 5£, 
°F, Not Exceeding 






Min. 
Tensile, 


Min. 
Yield, 






to 














Material 


Spec. No. 


Grade 


Class 


P-No. 


Notes 


E or F 


ksi 


ksi 


100 


150 


200 


250 


300 


350 


400 


Carbon Steel 
































Seamless Pipe and Tube 


ASTM A 53 


A 


S 


1 




1.00 


48.0 


30.0 


12.0 


12,0 


12.0 


12.0 


12.0 


12.0 


12.0 




ASTM A 53 


B 


S 


1 




1.00 


60.0 


35.0 


15.0 


15.0 


15.0 


15.0 


15.0 


15.0 


15.0 




ASTM A 106 


A 




1 




1.00 


48.0 


30.0 


12.0 


12.0 


12.0 


12.0 


12.0 


12.0 


12.0 




ASTM A 106 


B 




1 




1.00 


60.0 


35.0 


15.0 


15.0 


15.0 


15.0 


15.0 


15.0 


15.0 




API 5L 


A 




1 


(1) 


1.00 


48.0 


30.0 


12.0 


12.0 


12.0 


12.0 


12.0 


12.0 


12.0 




API 5L 


B 




1 


(1) 


1.00 


60.0 


35.0 


15.0 


15.0 


15.0 


15.0 


15.0 


15.0 


15.0 


Butt Welded Pipe and Tube 


ASTM A 53 




F 


1 


(2) 


0.60 


48.0 


30.0 


7.2 


7.2 


7.2 


7.2 


7.2 


7.2 


7.2 




API 5L 


A25 




1 


(1) 


0.60 


45.0 


25.0 


6.7 


6.7 


6.7 


6.7 


6.7 


6.7 


6.7 


Electric Resistance Welded Pipe 


and Tube 
































ASTM A 53 


A 


E 


1 




0.85 


48.0 


30,0 


10.2 


10.2 


10.2 


10.2 


10.2 


10.2 


10.2 






ASTM A 53 


B 


E 


1 




0.85 


60.0 


35.0 


12,8 


12.8 


12,8 


12.8 


12.8 


12.8 


12.8 






ASTM A 135 


A 




1 




0.85 


48.0 


30.0 


10.2 


10.2 


10,2 


10.2 


10.2 


10.2 


10.2 






ASTM A 135 


B 




1 




0.85 


60.0 


35.0 


12.8 


12.8 


12.8 


12.8 


12.8 


12.8 


12.8 






API 5L 


A25 




1 


(1) 


0.85 


45.0 


25.0 


9.5 


9.5 


9.5 


9.5 


9.5 


9.5 


9.5 






API 5L 


A 




1 


(1) 


0.85 


48.0 


30.0 


10.2 


10.2 


10.2 


10.2 


10.2 


10.2 


10.2 






APi 5L 


B 




1 


(1) 


0.85 


60.0 


35.0 


12.8 


12.8 


12.8 


12.8 


12.8 


12.8 


12.8 


Spiral Welded Pipe and Tube 


ASTM A 211 


A570-30 




1 


(3) 


0.75 


49.0 


30.0 


9.2 


8.4 


9.2 












ASTM A 211 


A570-33 




1 


(3) 


0.75 


52.0 


33.0 


9.8 


9.9 


9.8 














ASTM A 211 


A570-40 




1 


(3) 


0.75 


55.0 


40.0 


10.3 


9.4 


10.3 











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Si a 

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Material 



Carbon Steel (Cont'd) 
Forgings and Fittings 



Table i-1 Allowable Stresses (Cont'd) 



Strengths 



Spec. No. 



Type or 
Grade 



Class P-No. Notes 



Factor 
E or F 



Min. 

Tensile, 

ksi 



Min. 

Yield, 

ksi 



Max. Allowable Stress Value in Tension S£, 
ksi, for Metal Temperature, °F, Not Exceeding 



Oto 
100 



150 



200 



250 



300 







ASTM A 105 








ASTM A 181 


60 






ASTM A 181 


70 






ASTM A 234 


WPB 






ASTM A 234 


WPC 




Structural (4) 


ASTM A 36 






Bolts, Nuts, and Studs 








Ductile Iron Pipe 
Fittings and Couplings 


ASTM A 307 
ASTM A 377 


B 






ASTM A 395 


60-49-18 






ASTM A 536 


65-45-12 




Stainless Steel 








Seamless Pipe and Tube 








18Cr-8Ni 


ASTM A 312 


S30400 




18Cr-8Ni 


ASTM A 312 


S30400 




18Cr-8Ni 


ASTM A 312 


S30403 




18Cr-8Ni 


ASTM A 312 


S30403 




16Cr-12Ni-2Mo 


ASTM A 312 


S31600 




l6Cr-12Ni-2Mo 


ASTM A 312 


S31600 




16Cr~-12Ni-2Mo 


ASTM A 312 


S31603 




16Cr-12Ni-2Mo 


ASTM A 312 


S31603 




18Cr-13Ni-3Mo 


ASTM A 312 


S31700 




18Cr-13Ni-3Mo 


ASTM A 312 


S31700 



CD (3) 



(1)(5) 



58.0 



55.0 



36.0 



12,6 12.6 



7.0 



7.0 



12.6 



7.0 



12.6 



7.0 



12.6 



7.0 



0.80 


60.0 


40.0 


9.6 


9.6 


0.80 


65.0 


45.0 


10.4 


10.4 





1.00 


75.0 


30.0 


16.0 


(6) 


1.00 


75,0 


30.0 


16.0 


CD 


1.00 


70.0 


25.0 


13.3 


(D(6) 


1.00 


70,0 


25.0 


13.3 




1.00 


75.0 


30.0 


16.0 


(6) 


1.00 


75.0 


30.0 


16.0 


CD 


1.00 


70.0 


25.0 


13.3 


(1X6) 


1.00 


70.0 


25.0 


13.3 


CD 


1.00 


75.0 


30.0 


16.0 


(D(6) 


1.00 


75.0 


30.0 


16.0 



13.3 
15.1 
11.4 
13.3 
13.8 
16.0 
11.3 
13.3 
13.8 
16.0 



12.0 
14.1 
10.2 
13.0 
12.4 
15.6 
10.1 
13,3 
12.4 
15.6 



350 



12.6 



7.0 



400 





70.0 


36.0 


17.5 


17.5 


17.5 


17.5 


17.5 


17.5 


17.5 




60.0 


30.0 


15.0 


15.0 


15.0 


15.0 


15.0 


15.0 


15.0 




70.0 


36.0 


17.5 


17.5 


17.5 


17.5 


17.5 


17.5 


17.5 


1.00 


60.0 


35.0 


15.0 


15.0 


15.0 


15.0 


15.0 


15.0 


15.0 


1.00 


70.0 


40.0 


17.5 


17.5 


17.5 


17.5 


17.5 


17.5 


17.5 



12.6 



7.0 



11.0 

13.8 

9.3 

12.5 
11.4 
15.4 
9.2 
13.2 
11.4 
15.4 



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£. o 



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Table 1-1 Allowable Stresses (Cont'd) 









Size or 
Thickness, 






Strengths 




Max. Allowable Stress Value in Tension SE, 
ksi, for Metal Temperature, °F, Not Exceeding 






Min. 
Tensile, 


Min. 
Yield, 




Material and 


to 














Spec. No. 


Alloy 


Temper 


in. 


P-No. 


Notes 


ksi 


ksi 


100 


150 


200 


250 


300 


350 


400 


Aluminum and Aluminum 


Alloys 




























Drawn Seamless Pipe 


and Tubes 




























ASTM B 210 


3003 





0.010™0.500 


21 


CD 


14.0 


5.0 


3.4 


3.4 


3.4 


3.0 


2.4 


1.8 


1.4 


ASTM B 210 


3003 


H14 


0.010-0.500 


21 


CD (7) 


20.0 


17.0 


5.0 


5.0 


5.0 


4.9 


4.3 


3.0 


2.4 


ASTM B 210 


5050 





0.018-0.500 


21 


(i) 


18.0 


6.0 


4.0 


4.0 


4.0 


4.0 


4.0 


2.8 


1.4 


ASTM B 210 


6061 


T4 


0.025-0.500 


21 


(1)(8) 


30.0 


16.0 


7.5 


7.5 


7.5 


7.4 


6.9 


6.3 


4.5 


ASTM B 210 


6061 


T6 


0.025-0.500 


21 


(DCS) 


42.0 


35.0 


10.5 


10.5 


10.5 


9.9 


8.4 


6.3 


4.5 


ASTM B 210 


6061 


T4, T6 


0.025-0.500 


21 


Welded; (1)(9) 


24.0 




6.0 


6.0 


6.0 


5.9 


5.5 


4.6 


3.5 


Seamless Pipe and Seamless Extruded Tube 


























ASTM B 241 


3003 





All 


21 


CD 


14.0 


5.0 


3.4 


3.4 


3.4 


3.0 


2.4 


1.8 


1.4 


ASTM B 241 


3003 


H18 


< 1 


21 


(1X7) 


27.0 


24.0 


6.8 


6.8 


6.7 


6.3 


5.4 


3.5 


2.5 


ASTM B 241 


3003 


H112 


All 


21 


(D(7) 


14.0 


5.0 


3.3 


3.3 


3.3 


3.0 


2.4 


1.8 


1.4 


ASTM B 241 


5083 





Up thru 5.000 


25 


(D00) 


39.0 


16.0 


9.8 


9.8 












ASTM B 241 


5083 


H112 


Up thru 5.000 


25 


(D(io) 


39.0 


16.0 


9.8 


9.8 












ASTM B 241 


6061 


T4 


All 


23 


(DCs) (ID 


26.0 


16.0 


6.5 


6.5 


6.5 


6.4 


6.0 


5.8 


4.5 


ASTM B 241 


6061 


T6 


Ail 


23 


(D(8)(ll) 


38.0 


35.0 


9.5 


9.5 


9.5 


9.1 


7.9 


6,3 


4.5 


ASTM B 241 


6061 


T4, T6 


All 


23 


Welded; (1)(9)(11) 


24.0 




6.0 


6.0 


6.0 


5.9 


5.5 


4.6 


3,5 


ASTM B 241 


6063 


T6 


All 


23 


(1X8) 


30.0 


16.0 


7.5 


7.5 


7.4 


6.8 


5.0 


3.4 


2.0 


ASTM B 241 


6063 


T5, T6 


All 


23 


Welded; (1)(9) 


17.0 




4.3 


4.3 


4.3 


4.2 


3.9 


3.0 


2.0 



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OS K> 

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B * 

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B § 

& * 

3. o 



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Cfi 


hi 


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o 


O 


CD 


> 




CZ2 





Table i-1 Allowable Stresses (Cont'd) 

















Strengths 




Max. Allowable Stress Value in Tension 5E, 
«i, for Metal Temperature, °F, Not Exceeding 








Min. 
Tensile, 


Min. 
Yield, 






to 
















Material 


Spec. No. 


Alloy No. 


Condition 


P-No. 


Notes 


ksi 


ksi 


100 


150 


200 


250 


300 


350 


400 




Copper and Copper Alloys 


































Seamless Pipe and Tube 


































Copper Pipe, Size range NPS V 8 -2 incl. 


ASTM B 42 


102, 


122 


Annealed 


31 




30.0 


9.0 


6.0 


5.1 


4.8 


4.8 


4.7 


4.0 


3.0 




Copper Pipe, Size range NPS %-2 incl. 


ASTM B 42 


102, 


122 


Hard drawn 


31 


(12) 


45.0 


40.0 


11.3 


11.3 


11.3 


11.3 


11.0 


10.3 


4.3 




Copper Pipe, Size range NPS 2 1 / 2 -12 incl. 


ASTM B 42 


102, 


122 


Light drawn 


31 


(12) 


36.0 


30.0 


9.0 


9.0 


9.0 


9.0 


8.7 


8.5 


8.2 




Red Brass Pipe 


AST/Vl B 43 


230 




Annealed 


32 




40.0 


12.0 


8.0 


8.0 


8.0 


8.0 


8.0 


7.0 


5.0 


> 
in 


Copper Tube 


ASTM B 68 


102, 


122 


Annealed 




(1) 


30.0 


9.0 


6.0 


6.0 


5.9 


5.8 


5.0 


3.8 


2.5 


S 
rn 


Copper Tube 


ASTM B 75 


102, 


122 


Annealed 


31 




30.0 


9.0 


6.0 


5.1 


4.8 


4.8 


4.7 


4.0 


3.0 




Copper Tube 


ASTM B 75 


102, 


122 


Light drawn 


31 


(12) 


36.0 


30.0 


9.0 


9.0 


9.0 


9.0 


8.7 


8.5 


8.2 


t-4 


Copper Tube 


ASTM B 75 


102, 


122 


Hard drawn 


31 


(12) 


45.0 


40.0 


11.3 


11.3 


11.3 


11.3 


11.0 


10.3 


4.3 




Copper Tube 


ASTM B 88 


102, 


122 


Annealed 




(1) 


30.0 


9.0 


6.0 


5.1 


4.8 


4.8 


4.7 


4,0 


3.0 


o 
o 


Copper Tube 


ASTM B 88 


102, 


122 


Drawn 




(0(12) 


36.0 


30.0 


9.0 


9.0 


9.0 


9.0 


8.7 


8.5 


8.2 


00 


Brass Tube 


ASTM B 135 


230 




Annealed 


32 




40.0 


12.0 


8,0 


8.0 


8.0 


8.0 


8,0 


7.0 


5.0 




Copper Tube 


ASTM B 280 


102, 


122 


Annealed 




(1) 


30.0 


9.0 


6.0 


5.1 


4.8 


4.8 


4.7 


4.0 


3.0 




Copper Pipe, Threadless 


ASTM B 302 


102, 


122 


Drawn 




(1) 


36,0 


30.0 


9.0 


9.0 


9.0 


9.0 


8.7 


8.5 


8.2 





GENERAL NOTES: 

(a) 

(b) 

(c) 
(d) 
(e) 
(0 



See para. 902.3 for discussion of allowable stress values. 

The tabulated specifications are ASTM, except as noted. For boiler external piping, the corresponding ASME specifications shall be used. See Section II of the ASME BPV Code. 

The stress values may be interpolated to determine allowable stresses for intermediate temperatures. 

The P-Numbers indicated in this Appendix are identical to those adopted in Section IX of the ASME BPV Code. 

All stress values are shown in units of thousands of pounds-force per square in. (ksi). Multiply by 1000 to obtain values in psi. 

Materials listed in Table 926.1 for which allowable stress values are not tabulated in Appendix 1 may be used at allowable stresses found in ASME B31.1 or in Section I or Section 

VIII, Division 1 of the ASME BPV Code. However, the temperature limits in this Code shall apply. 



o 

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If 



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B $ 

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£- o 

S .2 



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i w 

p 



Table 1-1 Allowable Stresses (Cont'd) 



NOTES: 

(1) 
(2) 
(3) 



(4) 
(5) 

(6) 



(7) 
(8) 
(9) 
(10) 

(11) 
(12) 



This material is not acceptable for boiler external piping. See Fig. 900.1. 2B. 

ASTM A 53 Type F pipe shall not be used for flammable or toxic fluids. 

These stress values include a quality factor of 0.92 for structural material used in fabricating pressure containing components. Materials used in supports shall have an allowable 

stress value in tension of one-fifth the specified minimum tensile strength. 

Materials such as pipe listed elsewhere in Mandatory Appendix f may be used as structural material in accordance with para. 921. 

The specification provides wall thicknesses appropriate to the various diameters and combinations of pressure and laying condition. See ANSI/AWWA C150/A 21.50, Manual for 

the Thickness Design of Ductile Iron Pipe. 

Due to the relatively low yield strength of these materials, these higher stress values were established for use at temperatures where the short-time tensile properties govern, in 

order to permit the use of these alloys where slightly greater deformation is acceptable. The stress values in this range exceed 62 a / 2 % but do not exceed 90% of the yield strength 

at temperature. Use of these stresses may result in dimensional changes due to permanent strain. These stress values are not recommended for the flanges of gasketed joints or 

other applications where slight amounts of distortion can cause leakage or malfunction. 

The stress values given for this material are not applicable when either welding or thermal cutting is employed; in such cases, use the value for temper. 

The stress values for this material are not applicable when either welding or thermal cutting is employed; in such cases, use the values for the welded condition. 

Strength of reduced-section tensile specimen is required to quality welding procedure. See the ASME BPV Code, Section IX, QW-150. 

The supplier of material shall be consulted as to the ability of the alloy to withstand stress corrosion cracking under design conditions and combinations of stress and corrosive 

environments. 

For stress-relieved tempers (T351, T3510, T3511, T451, T4510, T4511, T651, T6510, T6511), stress values for material in the basic temper shall be used. 

Where brazed construction is employed, stress values for the annealed condition shall be used. 



> 
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AS/VIE B31.9-2008 



Table 1-2 Hydrostatic Design Stresses (HDS) and Recommended Temperature 
Limits For Thermoplastic Pipe 







Recommended 












Temperature 












Limits [Notes (1), (2)] 


Hydrostatic Design Stress at 










73°F, 






ASTM 




Minimum, 


Maximum, 


ksi 


100°F, 180°F, 


Spec. No. 


Material 


op 


°F 


[Note (3)] 


ksi 


<si 


D 1527 


ABS1210 


-30 


180 


1.0 


0.8 






ABS1316 


-30 


180 


1.6 


1.25 






ABS2112 


-30 


180 


1.25 


1.0 




D 2282 


ABS1210 


-30 


180 


1.0 


0.8 






ABS1316 


-30 


180 


1.6 


1.25 






ABS2112 


-30 


180 


1.25 


1.0 




D 2513 


AB51210 


-30 


180 


1.0 


0.8 






ABS1316 


-30 


180 


1.6 


1.25 






ABS2112 


-30 


180 


1.25 


1.0 




D 2846 


CPVC4120 





210 


2.0 


1.6 


0.5 


F 441 


CPVC4120 





210 


2.0 


1.6 


0.5 


F 442 


CPVC4120 





210 


2.0 


1.6 


0.5 


D 2513 


PB2110 





210 


1.0 


0.8 


0.5 


D 2662 


PB2110 





210 


1.0 


0.8 


0.5 


D 2666 


PB2110 





210 


1.0 


0.8 


0.5 


D 3000 


PB2110 





210 


1.0 


0.8 


0.5 


D 3309 


PB2110 





210 


1.0 


0.8 


0.5 


D 2104 


PE2306 


-30 


140 


0.63 


0.4 






PE3306 


-30 


160 


0.63 


0.5 






PE3406 


-30 


180 


0.63 


0.5 






PE3408 


-30 


180 


0.80 


0.5 




D 2239 


PE2306 


-30 


140 


0.63 


0.4 






PE3306 


-30 


160 


0.63 


0.5 






PE3406 


-30 


180 


0.63 


0.5 






PE3408 


-30 


180 


0.80 


0.5 




D 2447 


PE2306 


-30 


140 


0.63 


0.4 






PE3306 


-30 


160 


0.63 


0.5 






PE3406 


-30 


180 


0.63 


0.5 






PE3408 


-30 


180 


0.80 


0.5 




D 2513 


PE2306 


-30 


140 


0.63 


0.4 






PE3306 


-30 


160 


0.63 


0.5 






PE3406 


-30 


180 


0.63 


0.5 






PE3408 


-30 


180 


0.80 


0.5 




D 2737 


PE2306 


-30 


140 


0.63 


0.4 






PE3306 


-30 


160 


0.63 


0.5 






PE3406 


-30 


180 


0.63 


0.5 






PE3408 


-30 


180 


0.80 


0.5 




D 3035 


PE2306 


-30 


140 


0.63 


0.4 






PE3306 


-30 


160 


0.63 


0.5 






PE3406 


-30 


180 


0.63 


0.5 






PE3408 


-30 


180 


0.80 


0.5 





53 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



ASME B31.9-2008 



Table 1-2 Hydrostatic Design Stresses (HDS) and Recommended Temperature 
Limits For Thermoplastic Pipe (Cont'd) 







Recor 


amended 












Temperature 












Limits [Notes (1), (2)] 


Hydrostatic 


Design 


Stress at 










73% 






ASTM 




Minimum, 


Maximum, 


ksi 


100°F, 


180°F, 


Spec. No. 


Material 


°F 


°F 


[Note (3)] 


ksi 


ksi 




PP 


30 


210 








D 1785 


PVC1120 





150 


2.0 


1.6 






PVC1220 





150 


2.0 


1.6 








PVC2110 





130 


1.0 


0.8 








PVC2120 





150 


2.0 


1.6 






D 2241 


PVC1120 





150 


2.0 


1.6 








PVC1220 





150 


2.0 


1.6 








PVC2110 





130 


1.0 


0.8 








PVC2120 





150 


2.0 


1.6 






D 2513 


PVC1120 





150 


2.0 


1.6 








PVC1220 





150 


2.0 


1.6 








PVC2110 





130 


1.0 


0.8 








PVC2120 





150 


2.0 


1.6 






D 2672 


PVC1120 





150 


2.0 


1.6 








PVC1220 





150 


2.0 


1.6 








PVC2110 





130 


1.0 


0.8 








PVC2120 





150 


2.0 


1.6 







NOTES: 

(1) These recommended limits are for low pressure applications with water and other fluids that do 
not significantly affect the properties of the thermoplastic. The upper temperature limits are 
reduced at higher pressures, depending on the combination of fluid and expected service life. 
Lower temperature limits are affected more by the environment, safeguarding, and installation con- 
ditions than by strength. 

(2) These recommended limits apply only to materials listed. Manufacturers should be consulted for 
temperature limits on specific types and kinds of materials not listed, 

(3) Use these hydrostatic design stress (HDS) values at all lower temperatures. 



Table 1-3 Design Stress Values For Contact Molded (Hand-Lay-Up) Pipe Made 
From Reinforced Thermosetting Resins 











Stress Values, 


Material 








psi 


Spec. No. 


Resin 


Reinforcing 


Thickness, in. 


[Note (1)] 



ASTM C 582 



Polyester 



Glass fiber 


/s ~ /l6 


900 




% 


1 200 




Vl6 


1 350 




>% 


1 500 



NOTE 



(1) Stress values apply in the range -20°F to 180°F. 



54 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



ASME B31.9-2008 



Table 1-4 Hydrostatic Design Basis Stress for Machine-Made Thermosetting Resin Pipe 



ASTM Spec. 






No. and 






Type 


Grade 


Class 


D 2517 


Glass-fiber 


No liner 


filament 


reinforced 




wound 


epoxy resin, 
gas pressure 
pipe 






Glass-fiber 


No liner 




reinforced 






epoxy resin, 






gas pressure 






pipe 




D 2996 


Glass-fiber 


No liner 


filament 


reinforced 




wound 


epoxy resin 






Glass-fiber 


No liner 




reinforced 






epoxy resin 






Glass-fiber 


Epoxy resin 




reinforced 


liner, 




epoxy resin 


reinforced 




Glass-fiber 


Epoxy resin 




reinforced 


liner, 




epoxy resin 


reinforced 


D 2996 


Glass-fiber 


Polyester 


filament 


reinforced 


resin liner, 


wound 


polyester 
resin 


reinforced 




Glass-fiber 


Polyester 




reinforced 


resin liner, 




polyester 


reinforced 




resin 






Glass-fiber 


Polyester 




reinforced 


resin liner, 




polyester 


reinforced 




resin 




D 2996 


Glass-fiber 


No Hner 


filament 


reinforced 




wound 


polyester 
resin 






Glass-fiber 


No liner 




reinforced 






polyester 






resin 





Material 
Designation 

Number 
(ASTM 2310) 



Hoop Stress — 

Hydrostatic Design Basis 

73°F, psi [Note (1)] 



Cyclic 
[Note (2)] 



Static 
[Note (3)] 



RTRP-11AD 



RTRP-11AW 



RTRP-11AD 



RTRP-11AW 



RTRP-11FE 



RTRP-11FD 



RTRP-12EC 



RTRP-12ED 



RTRP-12EU 



RTRP-12AD 



RTRP-12AU 



5,000 



16,000 



5,000 



16,000 



6,300 



5,000 



4,000 



5,000 



12,500 



5,000 



12,500 



55 



Copyright © 2008 by the American Society of Mechanical Engineers. 
No reproduction may be made of this material without written consent of ASME. 



ASME B31.9-2008 



Table 1-4 Hydrostatic Design Basis Stress for Machine-Made Thermosetting Resin Pipe (Cont'd) 



ASTM Spec. 


Grade 


Class 


Material 
Designation 

Number 
(ASTM 2310) 


Hoop Stress — 

Hydrostatic Design Basis 

73°F, psi [Note (1)] 


No. and 
Type 


Cyclic 
[Note (2)3 


Static 
[Note (3)3 


D 2997 
centrifugally 


Glass-fiber 
reinforced 


Polyester 
resin liner, 


RTRP-22BT 




10,000 


cast 


polyester 
resin 


reinforced 










Glass-fiber 
reinforced 


Polyester 
resin liner, 


RTRP-22BU 




12,500 




polyester 


reinforced 










resin 












Glass-fiber 
reinforced 


Epoxy resin 
liner, 


RTRP-21CT 




10,000 




polyester 


nonreinforced 










resin 












Glass-fiber 
reinforced 


Epoxy resin 

liner, 


RTRP-21CU 




12,500 




polyester 


nonreinforced 










resin 











NOTES: 

(1) Service (design) factor must be applied to these values to obtain a hydrostatic design stress. 

(2) When using the cyclic design basis, the service factor shall not exceed 1.0. 

(3) When using the static design basis, the service factor shall not exceed 0.5. 



56 



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v No reproduction may be made of this material without written consent of ASME. 



ASME B31.9-2008 



MANDATORY APPENDIX II 
ALLOWABLE PRESSURES FOR NONMETALLIC, NONPLASTIC 

PRESSURE PIPING 



Table ll-l Alowable Pressures for f^onmetallic, Nonplastic Pressure Piping 



Spec. No. 



Material 



Class 



Allowable 

Gage 

Pressure, psi 



Maximum 
Temperature, 



ASTM C 361 



Reinforced concrete low 
head pressure pipe 



25 ft 

50 ft 

75 ft 

100 ft 

125 ft 



10 
20 

30 
40 
50 



AWWA C 300 


Reinforced concrete 
water pipe, steel 
cylinder type 




260 


AWWA C 301 


Prestressed concrete 
pressure pipe, steel 


Lined cylinder 


250 




cylinder type, for 


Embedded cylinder 


350 




water and other liquids 






AWWA C 302 


Reinforced concrete water 
pipe, noncylinder type 




45 



57 



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ASME B31.9-2008 



(08) 



MANDATORY APPENDIX ill 
REFERENCE STANDARDS 



Specific editions of standards incorporated in this Code by reference and the names and addresses of the sponsoring 
organizations are shown in this Appendix. This Appendix will be revised as needed. The names and addresses of 
the sponsoring organizations are also shown in this Appendix. An asterisk (*) indicates that the standard has been 
approved as an American National Standard by the American National Standards Institute (ANSI). 



AGA 

*A21. 14-84 
*A21 .52-82 
*Z223.1-92 

API 

5L, 38th Ed., 1992 
594, 3rd Ed., 1993 
609, 3rd Ed., 1993 

ASME 
*Bl.l-89 

& Bl.la-84 
*B1.20.1-83(R92) 
*B1.20.3-76(R82) 
*B1 .20.7-91 
*B16.1-89 
*B16.3-92 
*B16.4-92 
*B1 6.5-88 
*B1 6.9-93 
*B16.10-92 
*B16.11-91 
*B16.14-91 
*B16.1 5-85 
Bl.6.18-84 
*B16.21-92 
*B16.22-89 
*B1 6.24-91 
*B16.25-92 
*B1 6.26-88 
*B16.28-94 
*B16.33-90 
*B16.36-88 

& B16.36a-79 
*B16.39-86 
*B1 6.42-87 
*B18.2.1-81 
*B18.2.2-S7(R93) 
*B31.1-95 



ASME (Cont'd) 

*B31.3-96 

*B31.4-92 

*B31.5-92 

*B36.10M-95 

sf B36.19M-85(R94) 

*BPV Code, 1995 Ed. 

Section I 

Section II 

Section VIII, Division 1 

Section VIII, Division 2 

Section IX 

ASTM 

A 36/A 36M-89 

A 47-84(R89) 

A 48-83 

A 53-90a 

A 105-87a 

A 106-90 

A 126-84 

A 135-89a 

A 181/A 181M-87 

A 183-83(R90) 

A 193/ A 193M-90 

A 194/ A 194M-88a 

A 197-87 

A 211-75(R85) 

A 234/A 234M-90a 

A 254-90 

A 278-85 

A 307-90 

A 312-89a 

A 377-89 

A 395-88 

A 403/A 403M-89 

A 536-84(R93) 

A 539-90a 

B 26-88 

B 32-89 



ASTM (Cont'd) 

B 42-89 

B 43-88 

B 61-86 

B 62-86 

B 68-86 

B 75-86 

B 88-88a 

B 135-91 

B 210-88 

B 241-88 

B 247-88 

B 251-88 

B 280-86 

B 283-89 

B 302-87 

B 361-88 

B 547-88 

B 828-02 

C 361-93 

C 582-87 €l 

*D 93-90 

D 1527-89 

D 1598-86 

D 1694-87(91 61 ) 

D 1785-93 

D 2104-93 

D 2143-69(R87) 

D 2235-93a 

D 2239-93 

D 2241-93 

D 2282-89 

D 2310-91. 

D 2447-93 

D 2464-93 

D 2466-94 

D 2467-93 

D 2468-93 

D 2513-93a 

D 2517-81(87) 

D 2564-93 



58 



Copyright © 2008 by the American Society of Mechanical Engineers. 
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ASME B31.9-2008 



ASTM (Cont'd) 

D 2609-93 
D 2657-90 
D 2662-89 
D 2666-89 
D 2672-89 
D 2683-90 
D 2737-89 
D 2774-72(R83) 
D 2837-90 
D 2846-90 
D 2855-90 
D 2992-87 
D 2996-88 
D 2997-90 
D 3000-89 
D 3035-89a 
D 3138-93 
D 3139-89 
D 3140-90 
D 3261-90 
D 3309-93 
E 488-90 
F 402-93 
F 412-93 
F 437-93 
F 438-93 
F 439-93a 
F 441-93 
F 442-93 
F 493-93a 
F 876-00 
F 877-00 
F 1281-00 
F 1282-00 
F 1335-98 
F 2014-00 
F 2080-04 



AWS 
*A5.1-91 
*A5.2-92 
*A5.3-91 
*A5.4-92 
*A5.6-84(R91) 
*A5.8-92 
*A5.9-93 
*A5.10-92 
*A5.12-92 
*A5.17-89 
*A5.18-93 
*A5.2Q-94 
*A5.22-80(R89) 
*A5.23-90 
D10.9-80 



AWWA 

*C110/A21.10-93 

*Clll/A21.11-90 

*C150/A21.50-91 

*C151/A21.51-91 

C152-S1 [Note (1)] 
*C2Q7-94 
*C208-83 

& C208a-83 
*C300-89 
*C301-92 

C302-87 
*C500-93 
*C600-93 
*C606-87 
*C900-89 

CDA 

Copper Tube Handbook, 1980 



Federal Govt. 
WW-P-421D-76 



MSS 

SP-6-90 

SP-25-92 

SP-42-90(R92) 

SP-43-91 

SP-45-92 

SP-51-91(R95) 

SP-58-93 

SP-67-95 

SP-69-95 

SP-70-90 

SP-71-90 

SP-72-92 

SP-78-87(R92) 

SP-79-92 

SP-80-87 

SP-83-95 

SP-84-90 

SP-85-94 

SP-88-93 

SP-1 10-96 



NFPA 
*31-92 



SAE 

*J513f-92 

*J514~92 



GENERAL NOTE: In general, the issue date shown immediately following the hyphen after the number of the standard (e.g., B16. 10-73, A47- 
84, J514-80) is the effective date of the issue (edition) of the standard. Any additional number shown following the issue date and prefixed 
by the letter "R" is the latest date of reaffirmation [e.g., B1.20.3-76(R82), D1503-73(R78)]. 

A component or pipe conforming to an earlier material specification edition purchased by the user prior to the date of issuance of this 
Edition of the Code may be used, provided the component or pipe is inspected and determined to be satisfactory for the service intended. 
NOTE: 
(1) Out-of-print. 



59 



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ASME B31.9-2008 



Specifications and standards of the following organi- 
zations appear in this Appendix: 

AGA American Gas Association 

400 N. Capitol St., NW, Suite 450 
Washington, D.C. 20001 
202 824-7000 

API American Petroleum Institute 

Publications and Distribution Section 
1220 L Street, N.W. 
Washington, D.C. 20005 

202 682-8375 

ASME The American Society of Mechanical 
Engineers 
Order Department 
22 Law Drive, P.O. Box 2300 
Fairfield, NJ 07007-2300 
201 882-1167 

ASTM ASTM International 

100 Barr Harbor Drive 

P.O. Box C700 

West Conshohocken, PA 19428-2959 

610 832-9585 



AWWA American Water Works Association 
6666 W. Quincy Avenue 
Denver, CO 80235 
303 794-7711 

Federal Specifications: Superintendent of 

Documents 
United States Government Printing Office 
Washington, D.C. 20402 
202 783-3238 

CD A Copper Development Association, Inc. 
260 Madison Avenue 
New York, NY 10016 
212 251-7200 

MSS Manufacturers Standardization Society of 

the Valve and Fittings Industry 
127 Park Street, N.E. 
Vienna, VA 22180 
703 281-6613 

NFPA National Fire Protection Association 
1 Batterymarch Park 
Quincy, MA 02169 
617 770-3000 



AWS American Welding Society 

550 N.W. Lejeune Road 
Miami, FL 33126 
800 443-9353 



SAE Society of Automotive Engineers 

400 Commonwealth Drive 
Warrendale, PA 15096 
724 776-4841 



60 



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ASME B31.9-2008 



MANDATORY APPENDIX IV 
PREPARATION OF TECHNICAL INQUIRIES 



IV-l INTRODUCTION 

The ASME B31 Committee, Code for Pressure Piping, 
will consider written requests for interpretations and 
revisions of the Code rules, and develop new rules if 
dictated by technological development. The Commit- 
tee's activities in this regard are limited strictly to inter- 
pretations of the rules or to the consideration of revisions 
to the present rules on the basis of new data or technol- 
ogy. As a matter of published policy/ ASME does not 
approve, certify, rate, or endorse any item, construction, 
proprietary device, or activity, and, accordingly, inquir- 
ies requiring such consideration will be returned. More- 
over, ASME does not act as a consultant on specific 
engineering problems or on the general application or 
understanding of the Code rules. If, based on the inquiry 
information submitted, it is the opinion of the Commit- 
tee that the inquirer should seek professional assistance, 
the inquiry will be returned with the recommendation 
that such assistance be obtained. 

Inquiries that do not provide the information needed 
for the Committee's full understanding will be returned. 

The Introduction to this Code states, "It is the owner's 
responsibility to select the Code Section that most nearly 
applies to a proposed piping installation/' The Commit- 
tee will not respond to inquiries requesting assignment 
of a Code Section to a piping installation, 

IV-2 REQUIREMENTS 

Inquiries shall be limited strictly to interpretations of 
the rules or to the consideration of revisions to the pres- 
ent rules on the basis of new data or technology. Inquiries 
shall, meet the following requirements: 

(a) Scope. Involve a single rule or closely related rules 
in the scope of the Code. An inquiry letter concerning 
unrelated subjects will be returned. 



(b) Background. State the purpose of the inquiry, 
which would be either to obtain an interpretation of 
Code rules, or to propose consideration of a revision 
to the present rules. Provide concisely the information 
needed for the Committee's understanding of the 
inquiry, being sure to include reference to the applicable 
Code Section, Edition, Addenda, paragraphs, figures, 
and tables. If sketches are provided, they shall be limited 
to the scope of the inquiry. 

(c) Inquiry Structure 

(1) Proposed Question(s). The inquiry shall be stated 
in a condensed and precise question format, omitting 
superfluous background information, and, where 
appropriate, composed in such a way that "yes" or "no" 
(perhaps with provisos) would be an acceptable reply. 
The inquiry statement should be technically and editori- 
ally correct. 

(2) Proposed Reply (ies). Provide a proposed reply 
stating what it is believed that the Code requires. 

If in the inquirer's opinion a revision to the Code is 
needed, recommended wording shall be provided in 
addition to information justifying the change. 



IV-3 SUBMITTAL 

Inquiries should be submitted in typewritten form; 
however, legible handwritten inquiries will be consid- 
ered. They shall include the name and mailing address 
of the inquirer, and be mailed to the following address: 



Secretary 

ASME B31 Committee 

Three Park Avenue 

New York, NY 10016-5990 



61 



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No reproduction may be made of this material without written consent of ASME. 



ASME B31.9-2008 



NONMANDATORY APPENDIX A 
NONMANDATORY QUALITY SYSTEM PROGRAM 1 



Organizations performing Design, Fabrication, 
Assembly, Erection, Inspection, Examination, Testing, 
Installation, Operation, and Maintenance for B31.9 pip- 
ing systems shall have a written Quality System in accor- 
dance with applicable ISO 9000 Series documents. 
Registration or certification of the Quality System shall 
be by agreement between contracting parties involved. 

(a) ISO 9000-1:1994, Quality Management and 
Quality Assurance Standards — Part 1: Guidelines for 
Selection and Use 

(b) ISO 9000-2: 1993, Quality Management and 
Quality Assurance Standards — Part 2: Generic 



1 See para, 936.1.1. 



Guidelines for the Application of ISO 9001, ISO 9002, 
and ISO 9003 

(c) ISO 9000-3:1991, Quality Management and Quality 
Assurance Standards — Part 3: Guidelines for the 
Application of ISO 9001 to the Development, Supply, 
and Maintenance of Software 

(d) ISO 9001:1994, Quality Systems — Model for 
Quality Assurance in Design, Development, Production, 
Installation, and Servicing 

(e) ISO 9002:1994, Quality Systems — Model for 
Quality Assurance in Production and Servicing 

(f) ISO 9003:1994, Quality Systems — Model for 
Quality Assurance in Final Inspection and Test 



62 



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No reproduction may be made of this material without written consent of ASME. 



ASME B31.9-2008 



NONMANDATORY APPENDIX B 
SEISMIC DESIGN AND RETROFIT OF PIPING SYSTEMS 



(08) 



8-1 PURPOSE 

This Appendix establishes an alternate method for 
the seismic design of aboveground piping systems in 
the scope of ASME B31.9. 

B-l.l Scope 

This Appendix applies to aboveground, metallic, and 
nonmetallic piping systems in the scope of the ASME 
B31 Code for Pressure Piping, B31.9, Except for seismic 
design, the piping system in the scope of this Appendix 
shall comply with the materials, design, fabrication, 
examination, testing, and inspection requirements of 
ASME B31.9. 

B-1.2 Definitions 

active components: components that must perform an 
active function, involving moving parts or controls dur- 
ing or following the earthquake (e.g., valves, valve actua- 
tors, pumps, compressors, fans, that must operate 
during or following the design earthquake). 

axial seismic restraint: seismic restraint that acts along the 
pipe axis. 

critical piping: piping system that must remain leak tight 
or operable (see definitions) during or following the 
earthquake. 

design earthquake: the level of earthquake that the system 
must be designed for to perform a seismic function (posi- 
tion retention, leak tightness, or operability). 

free field seismic input: the seismic input without consider- 
ation for in-structure amplification at the facility 
location. 

in-structure seismic input: the seismic excitation within a 
building or structure, at the elevation of the piping sys- 
tem attachments to the building or structure. 

lateral seismic restraints: seismic restraints that act in a 
direction perpendicular to the pipe axis. 

leak tightness: the ability to maintain the pressure bound- 
ary of a piping system during or following the earth- 
quake. 

noncritical piping: piping system that meets the require- 
ments for position retention but may not be operable or 
leak tight during or following an earthquake. 

operability: the ability of a piping system to deliver, con- 
trol (throttle), or shut off flow during or after the design 
earthquake. 



position retention: the ability of a piping system not to 
fall, or collapse in case of design earthquake. 

seismic design: the activities necessary to demonstrate 
that a piping system can perform its intended function 
(position retention, leak tightness, or operability) in case 
of design earthquake. 

seismic function: a function to be specified by the engi- 
neering design either as position retention, leak tight- 
ness, or operability. 

seismic interactions: spatial or system interactions with 
other structures, systems, or components that may affect 
the function of the piping system. 

seismic response spectra: a plot or table of accelerations, 
velocities, or displacements versus frequencies or 
periods. 

seismic restraint: a device intended to limit seismic move- 
ment of the piping system. 

seismic retrofit: the activities involved in evaluating the 
seismic adequacy of an existing piping system and iden- 
tifying the changes or upgrades required for the piping 
system to perform its seismic function. 

seismic static coefficient: acceleration or force statically 
applied to the piping system to simulate the effect of 
the earthquake. 

B-1.3 Required Input 

(a) The scope and boundaries of piping systems to 
be seismically designed or retrofitted. 

(b) The applicable ASME B31.9. 

(c) The classification of piping as critical or noncriti- 
cal, and the corresponding seismic function (position 
retention for noncritical systems; leak tightness or opera- 
bility for critical systems). 

(d) The free field seismic input (commonly in the form 
of accelerations) for the design earthquake. 

(e) The responsibility for developing the in-structure 
seismic response spectra, where required. 

if) The operating conditions concurrent with the seis- 
mic load. 

(g) The responsibility for qualification of the operabil- 
ity of active components, where required. 

(h) The responsibility for the evaluation of seismic 
interactions. 

(i) The responsibility for as-built reconciliation of con- 
struction from the design documents. 



63 



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ASME B31.9-2008 



B-2 MATERIALS 

B-2.1 Applicability 

This Appendix applies to metallic or nonmetallic duc- 
tile piping systems listed in ASME B31.9. 

B-2.2 Retrofit 

The seismic retrofit of existing piping systems shall 
take into account the condition of the system and its 
restraints. The engineer shall evaluate the condition of 
the piping system and. identify and account for construc- 
tion imperfections and current and anticipated degrada- 
tion that could prevent the system from performing its 
seismic function. 



B-3 DESIGN 

B-3.1 Seismic Loading 

The seismic loading to be applied may be in the form 
of horizontal and vertical seismic static coefficients, or 
horizontal and vertical seismic response spectra. The 
seismic input is to be specified by the engineering design 
in accordance with the applicable standard (such as 
ASCE 7) or site-specific seismic loading (para. B-1.3). 

The seismic loading shall be specified for each of three 
orthogonal directions (typically, plant east-west, 
north-south, and vertical). The seismic design should 
be based on three-directional excitation, east-west plus 
north-south plus vertical, combined by square-root sum 
of the squares (SRSS), a two-directional design approach 
based on the envelope of the SRSS of the east- west plus 
vertical or north-south plus vertical seismic loading. 

The seismic loading applied to piping systems inside 
buildings or structures shall account for the in-structure 
amplification of the free field acceleration by the struc- 
ture. The in-structure amplification may be determined 
based on applicable standards (such as the in-structure 
seismic coefficient in ASCE 7), or by a facility specified 
dynamic evaluation. 

The damping for design earthquake response spec- 
trum evaluation of piping system shall be 5% of critical 
damping. A higher system damping value may be uti- 
lized such as provided by energy absorbing restraining 
systems if justified by test or analysis. 

B-3.2 Design Method 

The method of seismic design is given in Table B-3. 2.1. 
and depends on the following: 

(a) the classification of the piping system (critical or 
noncritical) 

(b) the magnitude of the seismic input 

(c) the pipe size 

In all cases, the engineer may select to seismically 
design the pipe by analysis, in accordance with para. 
B-3.4. 



B-3.3 Design By Rule 

Where design by rule is permitted in Table B-3.2. 1, 
the seismic qualification of piping systems may be estab- 
lished by providing lateral seismic restraints at a maxi- 
mum spacing given by 

L max - the smaller of (1.94 L T /a 025 ) and [0.0175 L T (S Y /a) 03 ] 

where 

a = maximum lateral seismic acceleration input 
to the pipe, g 
^max — maximum permitted pipe span between lat- 
eral and vertical seismic restraints, ft 
L T = reference span, the recommended span 
between weight supports, from ASME B31.1, 
Table 120.5 (reproduced in Table B-3.3.1), ft 
S y = material yield stress at operating temper- 
ature 

The maximum span, L max , between lateral seismic 
restraints for steel pipe with a yield stress Sy = 35 ksi, 
in water service, for several values of lateral seismic 
acceleration, a, is provided in Table B-3. 3.1. 

The maximum permitted span length, L max/ shall be 
reduced by a factor of 2.3 for threaded, brazed, and 
soldered pipe. 

Straight pipe runs longer than two times the span of 
Table B-3.3. 1 shall be restrained longitudinally. 

The piping system shall be sufficiently flexible to 
accommodate the differential movement of attachment 
points to the structure or the movement of equipment 
or headers to which the piping is attached. 

The distance between seismic restraints shall be 
reduced for pipe spans that contain heavy in-line compo- 
nents. 

Unrestrained cantiievered pipe shall be evaluated on 
a case-by-case basis. 

The effect of seismic restraints on the expansion and 
contraction flexibility of the piping system shall be veri- 
fied in accordance with the design rules of ASME B31.9. 

B-3.4 Design By Analysis 

Where design by analysis is required by Table B-3.2. 1, 
or where it is applied by the engineer as an alternative 
to the rules of para. B-3.3, the elastically calculated longi- 
tudinal stresses due to the design earthquake (calculated 
by static or dynamic analysis) shall comply with eqs, 
(B-3.4a) through (B-3.4c). 

(For Critical Piping) 



PD n 7R • ^sustained + 

4f Z 



M w 



= < 1.33S (B-3.4a) 



(For Noncritical Piping) 



PD ^ n 7t:,- ^sustained + ^sei< 

< min {3S; 2Sy, 60 ksi) 



(B-3.4b) 



64 



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ASME B31.9-2008 



Table B-3.2.1 Seismic Design Requirements, Applicable Sections 





Noncritical Piping 


Critical Piping 


Acceleration 


NPS < 4 in. 


MPS > 4 in. 


NPS<4 in. 


NPS>4 in. 


o<0.3g 


NR 


NR 


DR 


DA 




B-4 (interaction) 


B-4 (interaction) 


B-3.3 (rule) 

B-3.6 (mechanical joints) 

B-3.7 (restraints) 

B-4 (interaction) 


B-3.4/B-3.5 (analysis) 

B-3.6 (mechanical joints) 

B-3.7 (restraints) 

B-3.8 (component) 

B-4 (interaction) 


a >0.3g 


NR 


NR 


DA 


DA 




B-4 (interaction) 


B-3.3 (rule) 


B-3.4/B-3.5 (analysis) 


B-3.4/B-3.5 (analysis) 






B-3.6 (mechanical joints) 


B-3.6 (mechanical joints) 


B-3.6 (mechanical joints) 






B-3.7 (restraints) 


B-3.7 (restraints) 


B-3.7 (restraints) 






B-4 (interaction) 


B-3.8 (component) 
B-4 (interaction) 


B-3.8 (component) 
B-4 (interaction) 



GENERAL NOTES: 

(a) a = peak spectral acceleration, including in-structure amplification, g 

(b) NPS - nominal pipe size, in. 

(c) NR = explicit seismic analysis is not required, provided the piping system complies with the provisions of the applicable 
ASME B31 Code section, including design for loading other than seismic 

(d) DR - design by rule 

(e) DA = design by analysis 



Table B-3.3.1 Maximum Span (ft) Between 
Lateral Seismic Restraints for Steel Pipe With a 
Yield Stress of 35 ksi, in Water Service at 70°F 



M, 



NPS 


Lt 


0.1 g 


0.3 g 


1.0 g 


2.0 g 


3.0 g 


1 


7 


24 


18 


13 


11 


9 


2 


10 


34 


26 


19 


16 


13 


3 


12 


41 


31 


23 


19 


15 


4 


14 


48 


37 


27 


22 


18 


6 


17 


58 


44 


32 


27 


22 


8 


19 


65 


50 


36 


30 


25 


12 


23 


79 


60 


44 


37 


30 


16 


27 


93 


70 


52 


44 


35 


20 


30 


103 


78 


58 


48 


39 


24 


32 


110 


84 


62 


52 


42 



(For Critical and Noncritical Piping) 

-^SAM 



A 



■<Sv 



(B-3.4c) 



where 



A. 
D 

fsAM 



M fil 



pipe cross-sectional area, in. 2 

pipe diameter, in. 

resultant force (tension plus shear) due 

to seismic anchor motion and permanent 

deformation, kips 

stress intensification factor, from 

ASME B31.1 

elastically calculated resultant moment 

amplitude due to seismic load, including 

inertia and relative anchor motion, 

in.-kips 



sustained 



P 

s 



Sy = 
t = 

z = 



elastically calculated resultant moment 
amplitude due to sustained loads con- 
current with the seismic load, in.-kips 
system operating pressure, ksi 
ASME B31.9 allowable stress, at the nor- 
mal operating temperature, ksi 
specified minimum yield stress of the 
material, including weldments, brazed, 
and soldered joints, SMYS, ksi 
pipe wall thickness, deducting corrosion 
allowance but not mill tolerance, in. 
pipe section modulus, deducting corro- 
sion allowance but not mill tolerance, 



B-3.5 Alternative Design Methods 

Where eq. (B-3.4) cannot be met, the piping system 
may be qualified by more detailed analysis techniques, 
including fatigue, plastic, or limit load analysis. 

B-3.6 Mechanical Joints 

For critical piping systems, the movements (rotations, 
displacements) and loads (forces, moments) at mechani- 
cal joints (nonwelded joints unlisted in an ASME B16 
standard) must remain within the leak tightness limits 
specified by the joint manufacturer for leak tightness. 

B-3.7 Seismic Restraints 

The seismic load on seismic restraints and their attach- 
ment to building structures or anchorage to concrete 
shall be calculated by static or dynamic analysis and 
added to concurrent operating loads. 



65 



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ASME B31.9-2008 



The seismic adequacy of seismic restraints shall be 
determined on the basis of vendor catalogs, and the 
applicable design method and standard, such as 
MSS SP-58, MSS SP-69 for standard support compo- 
nents, A ISC or AISI for steel members, and ACT for 
concrete anchor bolts. 

The seismic adequacy of nonseismic restraints shall 
also be verified if they are expected to perform a function 
after the earthquake. For example, spring hangers 
should not be permitted to pull off the wall if they are 
necessary to support the pipe weight after the earth- 
quake. 

For lateral seismic restraints, a total diametral gap 
equal to \ in. is acceptable. A gap larger than % in., up 
to a diameter for MPS 2 and smaller pipe, and up to 
2 in. for pipe larger than NPS 2, is permitted, provided 
the seismic load, calculated on the basis of zero gap, is 
multiplied by an impact factor of 2. Larger gaps or 
smaller impact factors ma)/ be justified by analysis or 
test. 

Short rod hangers (typically less than 12 in. long) may 
provide a restoring force that tends to limit side-sway of 
hung pipe, and may be considered as seismic restraints, 
provided they are designed to sustain the seismic loads 
and movements. 

B-3.8 Equipment and Components 

The seismic and concurrent loads applied by the pipe 
at equipment and component nozzles shall be qualified 
as part of the seismic design or retrofit of the piping 
system, to a degree commensurate with the required 
system function, as specified in para. B-1.3. 

For position retention, it is usually sufficient to show 
that the piping loads on equipment and components 
will not cause rupture. For leak tightness, the stress shall 
be maintained within yield or shown not to cause fatigue 
rupture. For operability, the piping loads shall be kept 
within operability limits established by detailed analy- 
sis, testing, or similarity to seismically qualified equip- 
ment or components. 

B-4 INTERACTIONS 

Piping systems shall be evaluated for seismic interac- 
tions. Credible and significant interactions shall be iden- 
tified and resolved by analysis, testing, or hardware 
modification. 



B-5 DOCUMENTATION 

The engineering design shall specify the documenta- 
tion to be submitted by the engineer. 



B-6 MAINTENANCE 

The engineering design is responible for maintaining 
the configuration of the seismically qualified piping sys- 
tem. In particular, changes to layout, supports, compo- 
nents, or function, as well as material degradation in 
service, shall be evaluated to verify the continued seis- 
mic adequacy of the system. 

B-7 REFERENCES 

ACI 318, Building Code Requirements for Reinforced 
Concrete 

Publisher: American Concrete Institute (ACI), 38800 
Country Club Drive, Farming ton Hills, MI 48331 

Manual of Steel Construction 

Publisher: American Institute of Steel Construction, Inc. 

(AISC), One East Wacker Drive, Chicago, II, 

60601-1802 

Specification for the Design of Cold-Formed Steel 

Structural Members 
Publisher: American Iron and Steel Institute (AISI), 2000 

Town Center, Southfield, MI 48075 

ASCE 7, Minimum Design Loads for Buildings and 
Other Structures 

Publisher: American Society of Civil Engineers (ASCE), 
1801 Alexander Bell Drive, Reston, VA 20191-4400 

ASME B31.1, Power Piping 

ASME B31.9, Building Services Piping 

Publisher: The American Society of Mechanical 
Engineers (ASME), Three Park Avenue, New York, NY 
10016-5990; Order Department: 22 Law Drive, P.O. Box 
2300, Fairfield, NJ 07007-2300 

ICBO AC156, Acceptance Criteria for Seismic 
Qualification Testing of Nonstructural Components 

Publisher: International Conference of Building Officials 
(ICBO), 5360 Workman Mill Road, Whittier, CA 
90601-2298 

MSS SP-58, Pipe Hangers and Supports — Materials, 
Design, and Manufacture 

MSS SP-69, Pipe Hangers and Supports — Selection and 
Application 

MSS SP-127, Bracing for Piping Systems Seismic- Wind- 
Dynamic Design, Selection, Application 

Publisher: Manufacturers Standardization Society of the 
Valve and Fittings Industry, Inc. (MSS), 127 Park Street 
NE, Vienna, VA 22180-4602 



66 



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ASME B31.9-2008 



INDEX 



(08) 



abbreviations, 926.4 

acceptance standards/ 927.1 

access to the work, 936.2.1 

adhesive bond, 900.2, 934.1.1 

alarms, 922.1.2 

alignment, bolting, 935.2.1 

allowances, 902.4, 902.1 

aluminum pipe, Fig. 921.1. 3D, 923.2.4 

ambient influences, 901.4 

anchor, 900.2, 901.7, 920.1, 921.2.1, 935.11 

annealed temper, 923.2.4 

assembly, 900.2, 935.1 

automatic welding, 900.2; see also welding 

axes, 904.3.1 

backing, 900.2 

backing off, 935.4.4 

backing ring, 900.2, 911.1.1, 927.2.2 

ball joint, 900.2 

bars, hanger, 921.2.2(a) 

base material, 900.2, 917.1 

base metal, 900.2, 927.2.2 

bead, stringer, 900.2 

bead, weave, 900.2 

bellows, 900.3, 921.2.1 

bending, 929 

bending and torsion, 902.3.2 

bends, 906.2, 919.2.2 

bevel angles, 927.3.1, 927.4.2 

blanks, 904.5.1, 904.5.3, 908 

boiler external piping, 900.1.2, Fig. 900.1.2B, 926.1.1 

bolting engagement, 935.2.4 

materials, 902.3.1 

procedure, 935.2 

torque, 908.2 
borosilicate glass piping, 935.9 
branch connection 

definition, 900.2 

general, 904.3.1 

nonmetallic, 934.1.2 

welded, Fig. 927.4.6-1 
branch opening/ 904.3.2 
branch pipe, 904.3.1, 927.4.6, 934.2.3 
braze welding, 900.2; see also welding 
brazing qualification, 928.1.3 
brine, 900.2 

brittle failure, 900.2, 919.2.3, 923.3,2 
buckling, 921.2.1 

building services piping, 900.1.2(f) 
butt fusion, 934.1.3; see also welding 



butt joint, 900.2, 927.3.1 

butt weld, 902.2.2, Table 902.4.3, 911.1.1, 926.4, 927.3.1 



capacity, 919.2.3, Table 921.2.2A 

caps, 904.4.1 

cast, 904.3.1(b) 

cast iron, 902.3.1(b) and (d), 923.2.1, 923.2.2, 926.3 

cathodic protection, 902.4.1 

cements, 934.1.1 

centrifugally cast pipe, 934.2.2 

ceramics, 923.3.1 

certifications, 936.2.2 

chemical setting adhesive joints, 934.2.3; see also joint 

chilled water, 900.2 

chlorinated polyvinyl chloride (CPVC), Table 926.1, 

926.3, 934.1.2(a) and (b); see also plastic piping 
clamp-type joint, 913 
clamps, 921.2.2(c), 921.3.1 
cleaning, 927.3.1(b), 934.1.2(a) 
clevises, 921.3.1 
closures, 904.4.1 
coalescence, 900.2 
coatings, 902.4.1, 923.4 
Code computations, 902.3.1(a) 
cold spring, 919.6, 935.11 
column buckling strength, 921.2.1(c) 
combustible liquid, 900.1.2(a), 900.2 
commercial wall thickness, 904.1.2 
components, 902.2.1(b), 902.2.2, 902.2.3, 903, 926.1, 

Table 926.1 
compressed gas, 900.1.2(d), 905.2.1, 917.3.2, 923.3.2 
concrete, 921.5.1, 921.5.2 
consumable insert, 900.2 
continuous weld, see weld 
contour, 927.4.3 
contractor, 900.2 
cooling, 900.1.2, 901.4.1 
copper pipe, 905.2.3, Fig. 921.1.3, 923.2.3, Table 926.1, 

928.1.2 
corrosion allowance, 902.4.1 

control, 902.4.1 
crack, 900.2 
cradles, 921.3.1 
crevice corrosion, 914.2 
crosses, 904.3.1(a) 
cylindrical attachments, 921.3.2 

dampeners, 920.1.3 
dead weight, 920.1.1 



67 



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ASME B31.9-2008 



defect, 900.2 
definitions, 900.2 
deflection, 921.1.3(b) 
deposited metal, 900.2 
derating, 900.4.2 
design 

hydrostatic, 902.3.1(e) and (f) 

joint, 900.2 

minimum requirements for, 900.1.1 

pressure, 903, 904 

special, 903 
design conditions, 901, 902.2.4 
design criteria, 902, 903 
design methods, 902.4.4 

design pressure, 900.2, 901.1, 904.1.1(a), 926.2 
design requirements, 919.1 
design temperature, 900.2, 901.1, 902.2.3 
design thickness, 900.2 
deterioration in service, 923.5 
detrimental material, 927.3.1(b) 
diameter, 904.2.1(b) 
dimensional standard, 900.3 
direct connection, 904.3.1(c) 
division valve, 902.2.4 
drains, 937.3.2 
drip lines, 922.2.1 

ductile iron pipe, 904.1.1(b), 923.2.2, 926.3 
dynamic effects, 901.5 

ears, 921.3.2 

earthquake loads, 902.3.3, 920.1.1 

elbows, 919.2.2, Table 926.1 

electric resistance weld, Table 902.4.3 

end force, 902.3.2(e) 

end preparation, 927.3.1(a) 

engineer, 900.2, 904.1.1(a), 921.6, 923.5 

engineering calculations, 904.7,2 

engineering design, 900.2, 904.2.1(b), 927.1, 928.1.3, 

929.1, 934.3, 935.1, 936.2 
equipment connections, 900.2, 935.10 
erection, 900.2, 921.1.2, 935.1, 936.2.1, 936.4.1 
erosion, 914.2; see also corrosion 
examination, 900.2, 935.13, 936 
examiner, 900.2 
exclusions, 900.1.3 
expansion, 919, 921.5.2 
expansion joint, 900.2, 913, 919.2.2, 920.1.2(b), 

921.2.1(b) 
expected life, 902.4.1 
explosive actuated fasteners, 921.5.4 
external alignment, 927.4.2(b) 
extruded outlets, 904.3.1(a), 904.3.4, 930.2 

fabrication, 900.2, 927, 936.4.1 
fatigue, 919.1 
field erection, 935.1 



filler metal, 900.2, 927.2.1, 928.1.1 
fittings, 904.3.1(a), 906.1, Table 926.1 

butt welding, 902.2.2, 926.3, Table 926.1 

closure, 904.4.1 

forged steel or alloy threaded, 902.2.2 

outlet, 904.3.1(b) 
fixtures, 921.2, 934.1.3(a) 
flammable gas, 917.3.2 
flammable liquid, 900.2, 905.2.1, 906.3, 91.3.1, 917.3.2, 

923.3.2 
flange facing, 908.2 

flanges, 904.5, 908, 921.2.2(c), Table 926.1, 927.4.3(c) 
flat heads, 927.4.5, Fig. 927.4.5 
flexibility, 919 

fluid, expansion effects, 901.4.2 
fluid, incompressible, 904.5.3 
flux, 900.2, 928.1.1(b) 
forged couplings, 904.3.1(b) 
forming, 930 
formulas, 904.2.2(a) 
foundry tolerances, 904.1.1 
frictional forces, 920.1.2, 921.2.1(d) 
fusion, 900.2, 936.6.1 



gas pocket, 900.2 

gases, 913.1 

gasket, 908, 916.2 

gasket loading, 935.2.2 

gasket moment arm, 900.3 

gland-type joint, 913 

glass, 923.3.1, 935.9 

glass-to-glass connections, 935.9 

grooved joint, 913 

grooving allowance, see threading 

guides, 920.1, 921.2.1, 935.11 

hangers, 920.1, 921.2.2 

heat affected zone, 900.2 

heat fusion, 900.2 

heat treatment, 923.1.2, 927.4.6(d), 931 

hydraulic shock, 901.5 

hydrostatic design stresses, Mandatory Appendix I 

hydrostatic testing, 921.1.1(b), 937.1, 937.3, 937.4.3 

imperfection, 900.2, 927.1, 936.6 
indicators, 921.2.3(c) 
inert gas, 900.2 

initial operation, 919.6, 936.2, 937.1 
inlet temperature, 922.1.4 
inquiries, Mandatory Appendix IV 
inspection, 900.2, 936 
inspector, 900.2, 936.2 
insulation, 920.1.1, 921.3.1 
intentional displacement, 919.6 
internal alignment, 927.3.1(c) 



68 



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ASME B31.9-2008 



internal pressure tests, 904.3.2 
interpolation, Table 904.2.1, 904.7.2 
iron supports, 921.2.2 

joints 

bell and spigot, 916, 935.3 

brazed and soldered, 917, Table 917.3 

caulked or leaded, 916.1, 935.3.1 

compression, 935.7 

copper, Table 917.3 

corrugated, 920.1.2(b) 

flanged, 912, 935.2.1 

flared, flareless, and compression, 915, 934.1.4(a) 
935.7, 936.6.7 

hand lay-up, 934.2.4, 936.10 

heat fusion, 934.1.3 

limitations, 905.1.1, 906.1.1, 907.1.1 

mechanical, 900.2, 913, 935.8 

piping, 910 

proprietary, 913.1, 935.8 

push-type, 916.2 

rotary, 919.2.2 

slip, 920.1.2(b) 

socket- type, 911.1.2 

solvent cemented, 934.1.2 

steel-to-iron, 935.2.3 

swivel, 921.2.2(c) 

threaded, 911.1.4, 914, 923.2.4, 927.4.4, 935.4 

welded, 911, Mandatory Appendix I 
joint compound, 935.4.2 
joint deflection, 920.1.2(b) 
joint factor, 900.3, 902.3.1(a), Table 902.4.3 
joint penetration, 900.2, 936.6.1 

lapping, 930.1 
laterals, 904.3.1(a) 
leak testing, 937 
limits 

pressure, 900.1.2 

temperature, 900.1.2(b) 
linings, 923,4 
liquidus, 900.2 
live weight, 920.1.1 
loads, 902.3.2, 920.1, 921.2.1(a), 923.2.1 
loops, 919.2.2 
lubricant, 935.4.2 



machined surfaces, 902.4.2 

main, 900.2, 904.3 

main pipe wall, 927.4.6(c) 

malleable iron, 902.3.1(c), 921.2.2(c), Table 926.1, 926.3 

manufacturer, 936.3 

manufacturer's recommendations, 907.1.2 

manufacturing tolerance, 904.1.2(a) 

marking, 907.2 



materials, 902.3.1(d), 905.1.1, 907.1.1, 919.4.1, 922.3.1, 

923, 934.1.1 
may, 900.2 

mechanical strength, 902.4.4, 903, 910 
melting range, 900.2, 923.2.3 
metal temperature, 921.2.1(d) 
minimum thickness, 904.4.1 
misalignment, 921.2.3(b), 935.10 
miter angles, 904.2.2 
miter joint, 900.2, 904.2.2, 906.2, 927.3.1 
moduli of elasticity, Table 919.3.1 
moment of inertia, 900.3 
moments, 901.7, 919.7, 921.1 
movements, 919.5 
muitiaxial loading, 921.3.2 
multiple openings, 904.3.2(b) 

nomenclature, 900.3, Fig. 904.2.2 

nominal, 900.2 

nominal thickness, 900.2 

nonflammable, nontoxic liquid service, 904.2.2 

nonmetals, fabrication of NPS, 934 

nozzles, 904.3.1(b) 

nuts, 908.4 



operation, 902.3.3(a), 920.2.2 

operation conditions, 913 

"orange peel" reducer, see reducer, segmented 

O-ring joint, 913 

overpressure, 937.2.5 

overstress, 919.1, 921.1.1(b), 921.2.3(b) 

owner, rights of, 936.2.2 

oxidizing flame, 900.2 

oxygen cutting, 900.2, 923.3.2, 927.3.1(a) 

P-Numbers, Mandatory Appendix I 

pads, 927.4.6(d) 

pass, 900.2 

peel test, 900.2 

peening, 900.2 

permanent blank, see blank 

pipe 

discharge, 922.2.2 

limitations on, 905 

metallic, 902.4.2, 904.1.2, 911.1, 914.2, 91.9.4, 
Table 926.1 

nonmetallic, 904.1.1(c), 905.2.4, 911.2, 919.2.3 

plastic, 902.4.2, 904.1.1(c), 914.2, 921.1.3(d), 
Fig. 921.1.3D, 934.1 

supporting elements, 900.2, 920, 921.1, Mandatory 
Appendix 1 

threaded, 935.4.1 
pipe alignment guide, 900.2 
pipe bends, 904.2.1 
pivots, 921.2.1(a) 



69 



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ASME B31.9-2008 



plugs, 904.4.1 

pneumatic testing, 937.1, 937.4 

Poisson's ratio, 900.3 

polybutylene, 914.2, 926.1 

polyethylene, 914.2, 926.1, 934.1.3(b) 

polypropylene, 926.1, 934.1.3(b) 

porosity, 900.2 

postheating, 900.2 

preheating; 900.2, 927.4.1(b), 934.2.2 

pressure containing components, 904.7, 923.1.1, 

Mandatory Appendix I 
pressure design, 902.3.1, 926.2 
pressure reducing system, 922.1 
pressure surges, 901.2.1 
pressure-temperature, 902.2, 903, 913, 915, 923.2.2, 

Table 926.1 
pressures, 901.2.1, 902.3.2, 904.1.2, 922.1.1 
procedure, 900.2, 904.1.2, 921.3.2, 934.1.2(b) 
proof test, 904.7.2 
proportioning, 904.3.3 
purge gas, 900.2 
PVC, 926.1, 934.1.2 

qualification records, 927.6 
quality control, 907.1.2, 923.1.2, 936.1 
quality system program, 936.1.1, Nonmandatory 
Appendix A 

radiography, Table 902.4.3 

radius of gyration, 900.3 

ratings, 902.1, 902.2.3, 907.1.1 

recommend, 900.2 

reducer, segmented, 904.6.2 

reducing flame, 900.2 

reference standards, Mandatory Appendix III 

reinforcement, 900.2, 904.3.3, 927.4.6(d) 

repair of defective work, 934.3, 935.13 

restraint, 900.2, 901.7, 920.1.2 

resultant thermal movement, 900.3 

rings, 921.3.2 

root area, 921.1.1(a) 

root opening, 900.2, 927.3.1(d) 

root penetration, 900.2, 936.6.1 

root reinforcement, 900.2 

root surface, 900.2, 936.6.1 

RTR, 923.3.3, Table 926.1, 926.3, 934.2 

rubber, 923.3.1 

run, 900.2, 937.3.4(b) 

saddles, 921.3.1, 927.4.6(d), 934.2.3 
safety valve, 922.1.1 
sawtooth segments, 919.4.1(a) 
scope, 900.1 
sealers, 934.1.1 
seating surface, 914.1 



service conditions, 907.2, 917.1, 923.3.1, 935.4.2 

service limitations, 902.2.1(b) 

service record, 919.4.1(a) 

service testing, 937.1, 937.4.3, 937,5.2 

shall, 900.2 

shear lugs, 921.3.1 

shock, 914.2, 920.1.3, 921.2.3(c) 

shoes, 921.3.2 

shop erection, 935.1 

should, 900.2 

simplified analysis, 919.4.1(a) 

skirts, 921.3.2 

slag inclusion, 900.2 

slings, 921.3.1 

socket fusion, 934.1.3(b) 

solder, 900.2, Table 917.3, 928.2.1(a) 

soldering, 900.2, 917.1, 928,2 

solidus, 900.2 

solvent cement, 900.2, Table 926.1 

spacer strip, 900.2 

spacing, 921.1.3, 927.3.1(d) 

spatter, 900.2 

specific ratings, 902.2.1 

specifications and standards, 903, 923.1.1 

specified depth of cut, 902.4.2 

springs, 921.1.4, 921.2.3(c) 

stainless steel, 900.1.2(c), 926,3 

standard dimension ratio, 926.3 

standard practices, 926.2, Table 926.2 

steam service, 904.1.2, 922.1.2 

steel rods, threaded, Table 921.2.2 

stiffening requirements, 902.3.2(b), 904.1.2 

straight pipe thread, 914.1 

strap wrench, 935.4.5 

straps, 921.2.2(a), 921.3.1 

stress analysis, 904.7.2 

stress limits, 902.3 

stress-strain, 919.2.3 

stresses, 900.2, 902.3,2, 904.2.2, 906.1.1, 921.1.1, 923.1.2, 

Mandatory Appendix I 
structural attachments, 900.2, 921.3, 927.4.7 
supplemental steel, 900.2, 921.4 
support, 900.3, 919, 920.1, 921.1, Fig. 921.1. 3C, 935.11 
swaging, 930.1 
symbols, 900.3 



tapered pipe threads, 914.1 

tees, 904.3.1(a) 

temporary supports, 937.2.2 

tensile strength, 902.3.1(b), 921.1,1, 926.3 

terminal reactions, 919.7 

test conditions, 902.3.3(b), 904.5.3 

test loads, 920.2 

testing, see leak testing 

thermal cycling, 915 



70 



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ASME B31.9-2008 



thermal expansion and contraction, 901.7, 919.1, 

Table 919.3.1, 920.1.2, 921.2.3 
thermoplastic, 900.2, 902.3.1(e), 905.2.5, 911.2.1, 

923.3.2; see also plastic pipe 
thermosetting resin, 900.1.2(c), 900.2, 923.3.2 

926.3 
threading, 902.4.2, 921.1.1(a), 926.3, 935.3.1 
thrust, 921.2.1(a) 
thrust block, 900.2, 901.7 
tolerance, 902.4.2, 927.3.1(c) 
toxic, 917.3.2, 923.3.2 
tungsten electrode, 900.2 
turnbu.ckl.es, 921.1.2 

U-bends, 919.4.1(a) 
ultimate strength, 921.5.1 
ultrasonic examination, Table 902.4.3 
undercut, 900.2, 936.6.1(d), 936.6.2 

valve installation, 935.12 

valves, 907, 920.1.1, 922.1.2, Table 926.1 

vector forces, 920.1.2 

vents, 904.2.2, 927.4.6(d), 937.3.2 

vibration, 901.5, 914.2, 915 

visual examination, 936.4.1 



washers, 908.4 
water hammer, 904.1.1 
weight balance calculations, 921.2.3(a) 
weld 
926.1, defect, repairs of, 927.4.8 

fillet, 900.2, 911.1.3, 927.3.2, 936.6.2 

groove, 900.2, 927.4.6, 927.4.7 

longitudinal, 900.3, 904.6.2 

miter, 911.1.1, 927.3.1, 927.4.2 

seal, 900.2, 911.1.4, 914.1, 927.4.4, 935.4.3 
weld details, 927.4.6(b), Fig. 927.4.6-2 
weld joint efficiency factor, 902.4.3, 904.6.2 
voidability, 923.1.2, 928.2.1 
welder, 900.2, 911.1 
welder certification, 900.2 

Welder Performance Qualification, 900.2, 927.6.3 
welding, 900.2, Table 902.4.3, 904.3.1, 911.2, 926.3, 

927.4.2 
welding dimensions, Fig. 927.4.3-3 
welding operator, 900.2, 911.1, 927.5 
welding procedure, 900.2, 911.1, 927.5, 927.6, 931 
wetting, 900.2 

working pressure, 900.1.2(d), 922.1.2 
working temperature, 900.1.2(e) 



wall thickness, 900.3, 902.3.2(b), 904.2.1, Table 904.2.1A yield strength, 902.3.1(b), 904.5.3, 921.1.1(b) 



71 



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INTENTIONALLY LEFT BLANK 



72 



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ASME B31.9 INTERPRETATIONS 



ASME B31.9 INTERPRETATIONS 



Replies to Technical Inquiries 
January 2003 Through August 2007 

FOREWORD 

It has been agreed to publish interpretations isssued by the B31 Committee concerning B31.9 
as part of the update service to the Code. The interpretations have been assigned numbers in 
chronological order. Each interpretation applies to the latest Edition at the time of issuance of 
the interpretation or the Edition stated in the reply. Subsequent revisions to the Code may have 
superseded the reply. The interpretations are not part of the Code. 

These replies are taken verbatim from the original letters, except for a few typographical and 
editorial corrections made for the purpose of improved clarity. In some instances, a review of 
the interpretation revealed a need for corrections of a technical nature. In these cases, a revised 
reply, bearing the original interpretation number with the suffix R, is presented. In the case where 
an interpretation is corrected by Errata, the original interpretation number with the suffix E is used. 

ASME procedures provide for reconsideration of these interpretations when or if additional 
information is available which the inquirer believes might affect the interpretation. Further, 
persons aggrieved by an interpretation may appeal to the cognizant ASME committee or subcom- 
mittee. As stated in the Statement of Policy in the Code documents, ASME does not "approve/' 
"certify/ 7 "rate," or "endorse" any item, construction, proprietary device, or activity. 

For detailed instructions on the preparation of technical inquiries to the B31 Committee, refer 
to Mandatory Appendix IV. 



1-1 



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ASME B31.9 INTERPRETATIONS 



Interpretation: 9-13 

Subject: Initial Service Leak Testing (1996 Edition) 
Date Issued: October 26, 2006 
File: 06-37 

Question: Is initial service leak testing in lieu of a hydrostatic test permissible for a water 
system with a 150 psig design pressure, 150°F design temperature, and a maximum operating 
pressure of 100 psig? 

Reply: Yes; see para. 937.1. 



Interpretation: 9-14 

Subject: Paragraph 907.1.2, Use of Ball Valves Manufactured to MSS SP-110 (1996 Edition) 
Date Issued: August 1, 2007 
File: 07-1249 

Question: May bronze ball valves meeting the requirements of MSS SP-110 made from ASTM 
B 61, C92200 or ASTM B 62, C93600, be used for construction to the requirements of ASME 
B31. 9-2004? 

Reply: Yes. The manufacturer of the valve shall be responsible for establishing the pressure 
and temperature limits for their use. 

Interpretation: 9-15 

Subject: Paragraph 927.6.3, Welder Qualification (2004 Edition) 
Date Issued: August 21, 2007 
File: 06-1179 

Question: Does B31.9, para. 927.6.3, permit continuity records to be updated by the employer 
of a welder or brazer even though the welder or brazer's current employer may not be the same 
employer who qualified that welder? 

Reply: Yes. 



1-2 



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ASME CODE FOR PRESSURE PIPING, B31 



Power Piping . . . . B31. 1-2007 

Fuel Gas Piping B31.2 1 -1968 

Process Piping B31. 3-2006 

Pipeline Transportation Systems for Liquid Hydrocarbons and Other Liquids B31. 4-2006 

Refrigeration Piping and Heat Transfer Components B31. 5-2006 

Gas Transmission and Distribution Piping Systems B31. 8-2007 

Managing System Integrity of Gas Pipelines B31.8S-2004 

Building Services Piping B31. 9-2008 

Slurry Transportation Piping Systems. B31. 11-2002 

Manual for Determining the Remaining Strength of Corroded Pipelines: A Supplement to ASME B31 Code for Pressure Piping. . . B31G-1991 

Standard Test Method for Determining Stress Intensification Factors (/-Factors) for Metallic Piping Components B31J-2008 

Pipeline Personnel Qualification B31Q-2006 



NOTE: 

(1) USAS B31. 2-1968 was withdrawn as an American National Standard on February 18, 1988. ASME will continue to make available USAS 
B31. 2-1968 as a historical document for a period of time. 

The ASME Publications Catalog shows a complete list of all the Standards published by the Society. For a complimentary catalog, or the latest 
information about our publications, call 1- 800-TH E-ASME (1-800-843-2763). 



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lillliili 




ISBN-13 : 
ISBN-1Q: 



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9*78079111831328 



A11608 



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